Yokogi & Masui Partners > Tokyo, Japan > Firm Profile

Yokogi & Masui Partners
5th Floor, Toranomon Dai 2 Waiko Building, 2-6, Toranomon 5-chome Minato-ku

Japan > Tax: Independent local firms Tier 3

Yokogi & Masui Partners‘ tax department regularly advises clients on taxes levied on import transactions, such as consumption tax and customs duties, with the experienced duo Yoichi Masui and Kai Isoyama jointly leading the practice. Working alongside them is Seisuke Imai, who was promoted to partner in April 2023 and specialises in tax litigation.

Practice head(s):

Yoichi Masui; Kai Isoyama

Other key lawyers:


‘Yoichi Masui has deep experience and expertise in the area of import and export compliance. We can trust that his advice comes from both understanding of the law as well as experience in working with the customs officials and other relevant regulators.’

‘Each professional individual gives various opinions and appropriate advice as a team, which is useful for forming a mechanism for future goals.’

‘The main person who communicates with us is Yoichi Masui. Masui is very smart. He can sort out the complete link in his mind in a short time based on the client’s description. He has a unique communication method when dealing with tax and customs officials of the Japanese government, and has fully gained the trust of customs and tax agency staff.’

Japan > Labour and employment: Independent local firms Tier 4

Masatoshi Yokogi and Koji Kameda head up Yokogi & Masui Partners‘ team, which is known for its ‘clear focus on labour law and a steady accumulation of specialist knowledge and experience in this area’. Yokogi is highlighted as a ‘ professional, trustworthy, and sincere lawyer‘ and acts for a roster of domestic and global companies. The group’s strong knowledge of judicial precedents means that it is well placed to assist clients with day-to-day labour and employment issues.

Practice head(s):

Masatoshi Yokogi; Koji Kameda


‘They always provide effective and solid solutions based on rich experience and knowledge of difficult HR law in Japan which protects employees. Masatoshi Yokogi is the most professional, trustworthy, and sincere lawyer I have ever worked with. Highly recommended.’

‘The firm has a clear focus on labour law and a steady accumulation of specialist knowledge and experience in this area.’

‘Their experiences as in-house legal experts ensure that their advice on actual legal consultations maintains a good balance between the theoretical demands and the demands from a corporate practice.’

Japan > Real estate and construction: Independent local firms

Led by Akira Kubota, who is an expert in hotel development transactions, the real estate team at Yokogi & Masui Partners regularly advises on real estate transactions related to the development and construction of data centres.

Yokogi & Masui Partners was established in September 2010 by Masatoshi Yokogi and Yoichi Masui. The firm is engaged in general corporate matters since its establishment. Attorneys of the firm have various experiences especially in labour and employment, customs, tax, corporate, finance, real estate and international practice. The firm has expanded the range of practice areas and welcomed new members in order to provide appropriate and prompt legal advice in connection with various legal matters, and have made all efforts to contribute to and become close to all the clients facing legal matters.

Department Name Email Telephone
Labour and employment Masatoshi Yokogi
Labour and employment Koji Kameda
Tax Yoichi Masui
Tax Kai Isoyama
Real estate and construction Akira Kubota
Japanese; English