In 1999, Masaki Kato joined Tohmatsu Auditing (now Deloitte Touche Tohmatsu LLC), and in 2005, he joined Deloitte Tohmatsu Financial Advisory LLC, where he was engaged in M&A advisory services and business restructuring support services. After that, he worked for Regional Economy Vitalization Corporation of Japan and Shirai Sangyo Co.,Ltd. as President and Representative Director before joining Frontier Management Inc. in 2024.

After working as a domestic auditor at Deloitte Touche Tohmatsu LLC, he joined Deloitte Tohmatsu Financial Advisory LLC, where he was engaged in financial due diligence, business planning, and business valuation for M&A and business restructuring. He also provided consulting services for the non-profit sector (medical institutions, schools, and public corporations). During his tenure, he was transferred to the Corporate Research Department of Sumitomo Mitsui Banking Corporation, where he developed financial strategies and made proposals to listed companies.

At Regional Economy Vitalization Corporation of Japan, he was engaged in business and financial due diligence, formulation of business revitalization plans, fund management, sponsor selection and negotiation, and coordination with financial institutions in relation to business revitalization, and also participated in a project to establish a regional economic revitalization fund with the aim of developing and creating major regional industries and conducted investment operations.