Who We Are

MAST was founded in 2015, as a firm of professionals with various specialties and experience to provide One-Stop Total Legal Service.

Partner-led excellence from start to finish

MAST is a dynamic, specialized law firm where partners take direct, hands-on responsibility for every matter from start to finish. Our attorneys bring diverse experience as corporate executives, consultants, in-house counsel, and litigators, combining deep legal expertise with a practical understanding of business and management. On this foundation, MAST delivers differentiated, results-driven service across both advisory and litigation matters.

MAST succeeds when our clients succeed.

MAST's straightforward yet steadfast management principle is the foundation of the trust we have built since our establishment. What clients seek in a good law firm is one that treats their work as its own and dedicates itself wholeheartedly. MAST prioritizes the alignment of interests between clients and the firm to best serve client interests. As legal professionals, we uphold integrity and professional ethics as our highest priority, undertaking only advisory and litigation matters where client interests are fully aligned with ours.

Brand

A Name Forged in the Age of Discovery

In searching for a name that would define us, we found ourselves drawn to the great sailing ships that carried explorers and adventurers across uncharted seas during the 15th-century Age of Discovery — and to the mast and sail that gave those ships the power to move forward.

MAST exists to give our clients' journeys the momentum to move in the right direction.

The name MAST carries our commitment to be the partner who provides that forward momentum when clients face the storms of business and life, to fuel the frontier spirit of entrepreneurs, and to continue a rewarding voyage together with our clients.

The Meaning Behind Our Logo

The MAST logo combines our English name with a triangle symbolizing a sail — capturing the image of a sailing ship raising its sail and setting out across the open sea.

Testimonials

"A Highly Trusted Legal Partner with Top-Tier Expertise"

After founding Fresheasy and leading the fresh HMR/Mealkit business, I was looking for a reliable partner to help with complex legal issues when I was introduced to MAST Law & Consulting and Attorney Junghwan Lee. As Fresheasy grew from a small room to become the No. 1 company in the domestic fresh HMR sector through rocket-speed growth, MAST supported us like family, sharing every moment of joy and sorrow. Fresheasy raised hundreds of billions of KRW from numerous investors including VCs, PEs, and major conglomerates. MAST provided solid support in all areas, including M&A of subsidiaries, corporate financing for factory construction, asset sales, general commercial transactions, response to labor office investigations, HR/labor issues, corporate disputes, and litigation. Especially during the multi-hundred billion KRW Buy-out M&A deal with Anchor Equity Partners and subsequent Bolt-on M&As with Tasty9, Heodak, and Dr. Kitchen, they provided precise legal advice day and night based on their rich M&A experience and neatly resolved complex legal issues during the PMI process. Unlike general lawyers, I highly value their deep understanding of the inner workings of startups and companies, their meticulous response as if it were their own business, and their assistance in helping management make accurate decisions. MAST Law & Consulting, which has been with us since our founding, is the best law firm full of sincerity and passion, providing top-tier legal services to fast-growing companies and startups.

"A True Companion with Dedication and Expertise"

Many startup CEOs often ask me what criteria they should use when choosing a law firm. I always answer with "dedication" and "expertise." Many CEOs ask if there is a law firm that possesses both of those keywords. Without hesitation, I recommend MAST Law & Consulting. I remember when the A-ha team first formed a relationship with MAST. At that time, the company's situation was very poor. We met with numerous law firms, but they didn't even pay attention to us or listen deeply to our story. They seemed to think there was no money in it. However, Attorney Junghwan Lee at MAST war the only one who personally looked into our situation from beginning to end. Truly, from start to finish. Companies grow through repeated ups and downs. The A-ha team's journey has been a series of hardships and difficulties until achieving record sales and profits in 2023 and growing into a service with over 10 million MAU. I vividly remember him smiling and cheering us on, saying, "Fighting, CEO." That indescribable magnetic connection has continued for over 10 years now. Finding a law firm that possesses both a hot heart and a cool head is truly difficult for a manager, but MAST has established itself as a true companion on the A-ha team's long journey through dedication and expertise. They prioritize the client's interests and always worry for our success. MAST always monitors the latest trends and provides clear guidelines based on an in-depth understanding of the business, offering legal services that allow the A-ha team to focus solely on business. I feel happy and reassured to have MAST, with whom I can share a drink when times are tough and hug and cheer together when we are happy. MAST is a partner that has been, is, and will be seamlessly integrated into the A-ha team's success story. I would like to express my gratitude to MAST for consistently helping the A-ha team for such a long time.

"A Law Firm Like a Trusted Friend and Colleague for Critical Moments"

While dealing with major disputes that arose while managing Heodak, I was introduced to MAST Law & Consulting and Attorney Junghwan Lee. We were able to neatly resolve major dispute issues and successfully conclude the M&A with Fresheasy. Since then, operating the online HMR business, we have received help with changes in business content and structure, various disputes, lawsuits, and complex legal issues that occur frequently. MAST's strength is quickly grasping various problems and helping us make the best choices by considering various variables based on a high understanding of management and industry and rich experience. Unlike general lawyers who passively answer only what is asked, seeing them actively ask questions, listen to management's opinions, grasp the entire matter and issues like fitting a puzzle together, and find the optimal solution built a deep trust relationship. MAST helped create a preemptive crisis response system, which became a stepping stone for Heodak's rapid growth. The moments when a law firm is needed while doing business seem to be the most joyful moments and the most critical moments of crisis—the most dramatic and important moments. I am grateful to have met a true colleague and friend whom I can rely on in moments of crisis and who helps me make the right judgment with a calm mind in important moments.

"Highly Recommended: A Law Firm with Deep Business Understanding, Expertise, and Rich Experience"

After founding Breezm, we received investments from various investors, resulting in preferred stocks issued with different contents and numerous investment agreements. The US expansion and overseas investment attraction in 2024 became important milestones for the company's growth, and we received a lot of advice on overseas expansion and investment attraction. In particular, we were advised that legal work to unify investment agreements and preferred stock contents and align shareholders' rights was important before attracting overseas investment. We were introduced to MAST Law & Consulting and Attorney Junghwan Lee with strong recommendations from investment firms and CEOs of Kakao Investment portfolio startups. Before founding Breezm, I worked at a securities firm IB division handling M&A advisory and PE investment, so I was familiar with investments and M&A in the capital market and confident enough to review contracts myself. However, to make various investment agreements and shareholder agreements accumulated differently according to the rapidly changing startup investment environment and investment round situations advantageous and fair from the perspective of the company and founder, we proceeded with MAST, who possesses rich experience and high expertise. While working with MAST, looking at the analysis of nearly 20 different preferred stock contents, rights under shareholder agreements, and rights and obligations of the company and interested parties, I realized that I had been missing legally important things while focusing only on company growth. Based on the rich experience of MAST and Attorney Lee, we meticulously took care of management issues that could arise in the future growth process, and modified and consolidated almost all clauses to resolve potential problems in M&and corporate governance/management perspectives in advance. They provided options for responding to investors with different positions and explained them directly in investor meetings, allowing numerous meetings to proceed smoothly. After working with MAST during the overseas investment preparation process, we signed a regular advisory agreement to receive continuous legal advice. Having gained a truly trustworthy partner as a founder, I can now focus solely on company management and growth with a reassured mind. After working together, I understood why so many people strongly recommended MAST. I strongly recommend MAST Law & Consulting and Attorney Junghwan Lee to various startups and entrepreneurs.

"MAST Law & Consulting: A Firm You Can't Help But Recommend After Working Together"

While searching for a law firm to handle legal advice for XYZ's Series A investment attraction, I was recommended MAST Law & Consulting and Attorney Junghwan Lee by numerous startup CEOs. As a Venture Partner at FuturePlay directly investing in various startups and as an entrepreneur who has founded several startups, I know that investment terms and subsequent investment attraction results vary depending on the ability of the law firm handling the investment attraction advice. Therefore, I carefully selected the firm considering its expertise and proactiveness. MAST's strength is the proactiveness and responsibility to lead the work and preemptively identify and advise on problems that the client has not thought of. Unlike the investment attraction process which often proceeds in favor of investors, we were able to lead the investment negotiation based on Attorney Lee's rich investment round and M&A deal experience. Because they proposed investment structures, terms, and negotiation ideas that satisfied both the investors and us, we were able to smoothly conclude the complex negotiation process where both Financial Investors and Strategic Investors invested together, achieving satisfactory results. I believe MAST is the best partner capable of solving complex legal issues arising in corporate management from incorporation to M&A, knowing the position of startups and founders better than anyone based on rich experience and expertise. I hope you continue to be a solid partner for many startups and founders.

"The Most Reliable Law Firm on an Uncertain Business Path, a Solid Partner for Founders"

I was introduced to MAST during the most difficult period of business stagnation after founding a fintech startup. The growth of the existing business model was stagnant for a long time, and it was difficult to proceed with the devised business due to various financial regulations, so it was hard to find a direction. In that process, Attorney Junghwan Lee of MAST proposed solutions for related legal risks along with concerns about business strategy. With the new service and business model created in that process, we were selected for the Financial Services Commission's Innovative Financial Service last year, creating an opportunity to grow once again. Not only with expertise and experience but also because they worried with us more passionately than anyone else, it remains a grateful memory. We are receiving a lot of help through continuous legal advice on important company issues such as new service launches, Series B and C round investment attractions, and Open-up M&A. For fintech startups like ours that innovate the traditional financial industry based on digital technology, I believe MAST will be a more solid partner than any other law firm based on comprehensive experience and expertise in startups, IT, and finance sectors.

"Differentiation in Legal Services, Trusted Expertise, and Sincerity Felt from the Heart"

MAST Law & Consulting, Attorney Junghwan Lee, and Attorney Areum Han have been working with me since my time at Blank Corporation and now continue to work together at Makestar. As the CFO of Makestar, I work with MAST on everything from investment attraction and investor response, expansion into the entertainment business and various investments, launch of various new services and terms review, to complex dispute and litigation responses. While receiving legal advice from large law firms, boutique firms, and numerous lawyers, I often felt frustrated by answers like "It could be this, or it could be that," "Giving only theoretical answers instead of sharp answers to specific case questions," or "Answers that explain difficult problems even more difficultly." MAST, composed of lawyers with both a high understanding of the startup business environment and industry and legal expertise, advises company staff accurately and in an easy-to-understand manner. They provide optimal solutions from a problem-solving perspective, a differentiated strength that company members deeply trust. Personally, during the Series B investment round that took place shortly after I became CFO, they quickly grasped the various legal issues piled up in the company. They provided meticulous legal advice from investment agreement and shareholder agreement negotiations among numerous domestic and foreign investors to the closing process, presenting the best legal solutions. This was a great strength to me, and I was moved by the efforts of the lawyers who understood the position of the founder and the company, worried together, and solved problems. MAST Law & Consulting resolves the company's complex and difficult legal issues with the best legal service; they are a partner for mutual growth that you can trust.

"A Pillar of Support for Startups and IT Founders, MAST Law & Consulting"

My first connection with MAST Law & Consulting was through legal advice for the strategic investment attraction of the virtual asset exchange Bithumb. Through MAST's legal advice, I was able to accurately understand the meaning of unfamiliar legal terms in the shareholder agreement and the impact on subsequent investments regarding clauses such as RCPS, liquidation preference, and put options. There were ups and downs during the investment negotiation process, but based on MAST's advice, we were able to finish the investment round with good conditions. MAST와 함께 일을 해보고 나니 전문성과 업무태도 모두 신뢰할 수 있는 로펌이라는 확신이 들었습니다. 이후 회사 운영에 관련된 각종 자문, ZUZU 서비스 개발 및 출시에 대한 법률 자문, 서비스 약관 검토 등 제품 개발과 회사 성장에 필요한 모든 부분에서 도움을 받았습니다. 두나무와 진행한 코드박스 M&A 과정에서도 법무법인 마스트와 이정환 변호사님의 법률자문을 받아 창업자에게 유리한 조건으로 협상하고 계약을 체결하여, M&A 딜을 성공적으로 마무리 할 수 있었습니다. 투자, M&A, 신사업 검토, 각종 분쟁해결, 규제검토 등 수많은 기업과 스타트업의 법률 자문을 담당한 경험에서 자연스럽게 느껴지는 마스트의 실력은 다른 변호사들이 쉽게 따라올 수 없는 마스트의 가장 큰 경쟁력이라고 생각합니다. 어떤 분야든 실력 있는 회사, 실력 있는 사람을 만나는 일은 쉽지 않습니다. 다른 대표님들이 로펌을 추천해 달라고 하면 저는 자신 있게 마스트와 이정환 대표 변호사님을 추천합니다.

"A Partner for Mutual Growth with Expertise, Proactiveness, and Sincerity"

I was recommended MAST and Attorney Junghwan Lee while selecting a law firm to handle the Ridi-Laftel M&A. After working with various law firms including large firms on M&A, investment, and various legal issues, I learned that the results of the work vary depending on the law firm in charge. In particular, the structuring of the Ridi-Laftel M&A was not easy, so we had preliminary meetings with many law firms and selected MAST, who proposed the optimal structure, as our legal counsel. Working together during the M&A process, I was impressed by MAST's dedication to preemptively identifying issues that the client had not thought of, unresolved issues, and even long-term impacts, and doing their best to find optimal solutions. Since forming a relationship at Ridi, legal advice for startups has always been with MAST. In particular, they neatly resolved complex issues arising from Gowid's governance improvement work, and I highly evaluate their fast and accurate advice throughout the entire process of attracting investment, negotiating, and signing various contracts for Finda's Series C round, where a domestic financial holding company participated as an SI and an overseas VC as an FI. The MAST I have worked with is a law firm that does its best for the client's success based on "expertise," "proactiveness," and "sincerity," and is a partner that entrepreneurs and startups can trust.

"A Law Firm That Proves Itself to Clients Through Process and Results"

Since founding Rarajob, working with MAST Law & Consulting on two investment attractions and an M&A deal, we were able to successfully complete the startup lifecycle. Startup founding and investment attraction were not new to me, but knowing that a seemingly minor clause or phrase could have a significant impact on the future of the company and the founder, I started working with MAST upon recommendations from surrounding CEOs. When reviewing investment deals, MAST exercises strong leadership so that the founder can make the right decisions considering future scenarios such as follow-up investment, M&A, and IPO. Thanks to MAST considering these situations in advance, the subsequent follow-up investment and M&A could proceed smoothly. The M&A was conducted with SaraminHR, a listed company. We went through a long negotiation from acquisition structure to acquisition conditions, final contract signing, and closing, and went through numerous adjustments on M&A conditions. Each time, MAST helped find a compromise by presenting various counter-conditions based on expertise and diverse M&A experience. For matters that were difficult for me to explain to existing shareholders or the acquirer SaraminHR, they explained directly through meetings and participated in negotiations, doing their best to support the successful completion of the M&A deal. I will never forget the memory of talking about trivial things while breathing the dawn air on the law firm's rooftop, discussing response strategies for key M&A issues and contract revisions with Attorney Lee the night before the final negotiation with SaraminHR. To CEOs looking for a law firm for founders and startups, I sincerely recommend MAST Law & Consulting.

"The Best Legal Partner Protecting Founders and Startups"

I was recommended MAST and Attorney Junghwan Lee during the process of attracting Series B round investment. It was an investment attraction round with high volatility in investment conditions due to worsening market conditions, and the situation was daunting with legal due diligence, unification of investment contract conditions between existing and new investors, and integration of shareholder agreements. After months of negotiation, I received a lot of help to make a rational contract that fairly reflected the needs of the company, founder, and investment firm. Although it was a new investment round, since it was done while integrating investment agreements and shareholder agreements, seeing them explain how to change everything from various toxic clauses I didn't understand when signing existing contracts to unreasonable clauses I had to sign knowingly, by dividing them into Best to Worst case options, was a great strength. When it was difficult for me, not knowing the law well, to persuade investors, they directly explained numerous questions through meetings with investors and wrote opinion letters. Investors also acknowledged MAST's opinions as reasonable, so we were able to modify most of the unfair clauses for the founder and company in existing investment agreements and shareholder agreements, and receive investment from new investors under the same conditions, for which I was sincerely grateful. They know exactly the various issues that arise at each stage of company growth through long experience and know-how in the startup field, and possess rich experience in investment rounds and M&A. It was impressive how they created a solution that investors could accept while providing agreed proposals by scenario that could guarantee investors' rights while reducing legal risks and unfavorable contents from the perspective of the founder and startup. Since the Series B investment, we have signed a legal advisory contract and are managing legal risks by receiving legal advice on overall corporate management, including overseas expansion, product export, new business, factory construction-related legal disputes, and HR. MAST Law & Consulting is a law firm for which I am so grateful and reassured as a founder, giving unsparing advice with expertise, adeptness, preemptive response, and sincerity in a direction that allows the company to grow correctly.

"The Best Partner That Corporate Legal Managers Have No Choice But to Trust"

Starting with the revision of the important "Company Service Terms and Conditions" when there was no in-house lawyer in the legal organization, I worked with MAST Law & Consulting to solidify the compliance organization for proactive risk reduction, beyond civil/criminal, fair trade, copyright, and M&A feasibility reviews. MAST Law & Consulting and Attorney Junghwan Lee were supporters and partners as reassuring as in-house colleagues sharing joys and sorrows. Being an IT company, discussions for advice or legal solutions usually involve IT terminology and Technical Skills. While communication was somewhat difficult with other law firms and considerable resources were invested in preparing basic data, collaboration with MAST, who has diverse experience in IT as well as new businesses and global issues, proceeded smoothly and quickly without wasting these resources. Also, it was impressive that we were able to obtain the best results thanks to the excellent lawyers possessed by MAST in global legal issues and global dispute issues in English and Japanese speaking regions. They are the best partners who strive day and night to think deeply and seriously about the case and derive a solution immediately and quickly whenever urgent business and legal issues need to be reviewed. I have many memories of being grateful and sorry for their response with a voice that sounded like they had worked all night when I contacted them early in the morning. Beyond general legal work, at the time of planning and establishing the compliance system, the advice appropriate for our organization and unreserved advice based on the collaboration experience and know-how with startups, SMEs, mid-sized companies, large corporations, and companies that rose to the rank of large corporations at once with explosive growth potential, which only MAST has consistently done, was the hidden foundation that allowed the organization to be systematized and stabilized within a short period. Regardless of what legal (compliance) issues arise, if you can work with MAST Law & Consulting, I can confidently recommend that it will be the best in terms of process and result.

"A Law Firm That Supports You Reliably from a Founder's Perspective with Expertise, Passion, and Comfort"

Startups attempt new things based on their respective business and technical expertise, but they face difficulties due to lack of experience and unfamiliar situations in the process of such business attempts and attracting investment. RideFlux is a startup pioneering the mobility sector based on autonomous driving technology. After securing our seed funding from Socar and Soqri, we were fully immersed in core tech R&D. However, advancing into a highly institutional Series A round with top-tier VCs presented massive strategic and legal challenges for me as a CEO. We partnered with MAST following a strong endorsement from our early investor, Soqri. Backed by extensive transactional experience, MAST provided crystal-clear legal breakdowns of complex term sheets and structured actionable workarounds. Instead of delivering passive, transactional legal reviews, they looked at our capitalization table from a macroscopic scaling perspective, engineering creative win-win deal terms that perfectly aligned the incentives of the company, the founders, and institutional investors. What's more, I sincerely thank them for allowing me to consult with a comfortable mind and responding passionately regardless of day or night. I hope many startups can achieve their dreams with MAST, which provides accurate legal advice for founders with expertise and affection for startups.

"The Best Law Firm That Cries and Laughs Together and Grows with Clients"

MAST and Attorney Junghwan Lee have been with the life of the corporation called Accio from company establishment to legal review for product launch, business contracts, and M&A. When establishing a company, the shareholder agreement between co-founders is very important. Everyone starts with one mind when starting, but since unexpected things happen while running a company, the importance of this contract is emphasized a lot. I believe the trust relationship between co-founders greatly influences the content of the contract in writing this shareholder agreement. MAST did not write a cookie-cutter shareholder agreement but closely grasped the relationship between our Accio founders and melted it well into the contract. With this as an opportunity, we started to build a good trust relationship with MAST. Trust became even thicker while proceeding with the M&A contract between Kakao and Accio. It was a difficult time taking over 6 months for acquisition negotiation. In this process, sharing various emotions—laughing together, sometimes getting angrier than us—we were able to overcome difficult times together and achieve good results. Utilizing the expertise experienced in multiple M&As, they made a lot of efforts in various ways, not only reviewing and modifying contracts but also advising on the overall negotiation and responding to Kakao managers. Also, they understood well my relationship with Kakao, having already sold a company to Kakao once, and proceeded with the M&A deal so that such content could be reflected well. Even now, we are receiving MAST's legal advice on the overall parts of Accio, such as joint business contracts with the parent company and legal review for new service launches, and we will be together on the future journey. I would like to recommend MAST to all IT entrepreneurs and startup CEOs who need legal advice.

"The Best Law Firm for Startups"

For GymT, which had to worry about full-scale growth past the initial stage, MAST's legal advice was truly a great help. Proceeding with the Series A investment round with multiple investors together with Attorney Junghwan Lee, we were able to overcome numerous difficulties and receive investment under good conditions desired by the founders. They reviewed various corporate legal matters such as investment agreements, shareholder agreements, articles of incorporation, and stock options very meticulously and accurately. During investment negotiations, they presented various legal solutions that satisfied both the company and investors based on rich experience, allowing us to finish the difficult negotiation process well. With an attitude of working as one mind from the customer's perspective and explaining difficult legal issues easily and accurately in a comfortable atmosphere, decision-making as a CEO became much easier. Please continue to be a good partner for startups in the future!

"MAST, A Companion for Startups"

Service development, 고도화 등 핵심에만 집중하기에도 벅찬 스타트업을 운영하면서 법률적인 부분까지 신경쓰는 것이 힘들었고, 회사를 운영하다가 발생한 중요한 소송에서 대표님들의 추천을 받아 마스트와 일을 하게 되었습니다. 회사경영에 중대한 영향을 미치는 소송에서 마스트의 변호사님들이 열정적으로 의뢰인의 편에서 일 하시는 모습과 여러 문제 해결하고 좋은 결과로 이끌어주시는 것을 경험하면서 마스트와 깊은 신뢰관계를 형성하게 되었습니다. 이후 VC 투자유치, 각종 분쟁과 민형사소송, 대관업무, 기업법무 등 회사 경영에서 발생하는 모든 법률이슈를 마스트에서 해결주셨고, 항상 좋은 결과를 얻게 되어 과외중개 서비스 시장에서 “김과외” 가 시장 1위로 도약하는데 큰 도움을 받았고 진심으로 감사한 마음을 가지고 있습니다. 한결같이 고객의 입장에서 고민해주시고, 진정성있게 스타트업 클라이언트를 아껴주시는 마스트, 많은 창업가들에게 추천드립니다.

"A Law Firm More Comfortable and Accurate Than Any Other"

I was introduced to Attorney Junghwan Lee during a legal dispute with an M&A advisor during the sale of Thebanchan and received valuable advice. Since then, founding PurpleLabs and working with MAST, I have received a lot of help in various fields such as legal advice on various issues arising in overall management, civil litigation and dispute response, investment attraction and negotiation, and stock options. Having worked with various law firms and met many lawyers, I liked MAST because it was not a stiff and rigid law firm, and I felt a lot of comfort. So I was able to confide in various worries more and receive accurate legal advice. I hope you establish yourself as a solid partner who grows with and supports all startups and founders!