March	1948	Yachiyo Securities Co., Ltd., established
April	1968	Yachiyo Securities obtained a securities license under the revised Securities and Exchange Law of Japan
October	1981	Yachiyo Securities, Koa Securities Co., Ltd., and The Nomura Securities Investment Trust Sales Co., Ltd., merged to form KOKUSAI Securities Co., Ltd.
March	1983	KOKUSAI Investment Trust Management Co., Ltd., established
May	1987	KOKUSAI Securities listed on the Second Section of the Tokyo, Osaka, and Nagoya stock exchanges
March	1989	KOKUSAI Securities listed on the First Section of the Tokyo, Osaka, and Nagoya stock exchanges
June	1990	KOKUSAI Computer System Co., Ltd., established (currently MUS Information Systems Co., Ltd.)
October	1994	<Mitsubishi Diamond Securities Co., Ltd., established (renamed to Tokyo-Mitsubishi Securities Co., Ltd., in April 1996)>
July	1997	KOKUSAI Investment Trust Management and KOKUSAI Investment Management merged to form KOKUSAI Asset Management Co., Ltd.
December	1998	KOKUSAI Securities registered as a securities company under the revised Securities and Exchange Law of Japan
July	1999	<Tokyo-Mitsubishi Securities took over and integrated all business operations of Mitsubishi TB Securities Co., Ltd.>
April	2000	<Universal Securities Co., Ltd., Taiheiyo Securities Co., Ltd., Towa Securities Co., Ltd. and Dai-ichi Securities Co., Ltd., merged to form Tsubasa Securities Co., Ltd.>
June	2002	<Tsubasa Securities and UFJ Capital Markets Securities Co., Ltd., merged to form UFJ Tsubasa Securities Co., Ltd.>
July		KOKUSAI Securities took minor interest to form Mitsubishi-Tokyo Wealth Management (Switzerland) (currently Mitsubishi UFJ Wealth Management Bank (Switzerland), Ltd.)
September		KOKUSAI Securities, Tokyo-Mitsubishi Securities, Tokyo-Mitsubishi Personal Securities Co., Ltd. and Issei Securities Co., Ltd., merged to form Mitsubishi Securities Co., Ltd., which simultaneously became a subsidiary of The Bank of Tokyo-Mitsubishi, Ltd., (currently MUFG Bank, Ltd.) and Mitsubishi Tokyo Financial Group, Inc.
May	2003	Tokyo-Mitsubishi International (Singapore) Ltd, became a subsidiary of Mitsubishi Securities (currently MUFG Securities Asia Limited)
June		Tokyo-Mitsubishi International (HK) Limited, became a subsidiary of Mitsubishi Securities (currently MUFG Securities Asia Limited)
July		Tokyo-Mitsubishi Securities (USA), Inc., became a subsidiary of Mitsubishi Securities (currently MUFG Securities Americas Inc.)
July	2004	Tokyo-Mitsubishi International plc, became a subsidiary of Mitsubishi Securities (currently MUFG Securities EMEA plc)
July	2005	Mitsubishi Securities became a directly owned subsidiary of Mitsubishi Tokyo Financial Group (currently Mitsubishi UFJ Financial Group, Inc.)
October		Mitsubishi Securities and UFJ Tsubasa Securities merged to form Mitsubishi UFJ Securities Co., Ltd. As a result of the merger, UFJ Tsubasa Business Service Co., Ltd (currently MUS Business Service Co., Ltd.) became subsidiaries of Mitsubishi UFJ Securities.
September	2007	Mitsubishi UFJ Securities became a wholly owned subsidiary of Mitsubishi UFJ Financial Group (As a result, Mitsubishi UFJ Securities stocks were delisted.)
December		Mitsubishi UFJ Wealth Management Bank (Switzerland), Ltd. became a subsidiary of Mitsubishi UFJ Securities
March	2008	KOKUSAI Asset Management became a consolidated subsidiary of Mitsubishi UFJ Securities
December	2009	Mitsubishi UFJ Securities Spin-off Preparation Co., Ltd. established
April	2010	Mitsubishi UFJ Securities transferred its domestic operations to Mitsubishi UFJ Securities Spin-off Preparation, by way of a split (absorption-type company split), became an intermediate holding company and renamed to Mitsubishi UFJ Securities Holdings Co., Ltd. Mitsubishi UFJ Securities Spin-off Preparation was renamed to Mitsubishi UFJ Securities Co., Ltd.
May		Mitsubishi UFJ Securities and the investment banking division of Morgan Stanley Japan Securities (currently Morgan Stanley MUFG Securities Co., Ltd.) integrated to form Mitsubishi UFJ Morgan Stanley Securities Co., Ltd.
December	2012	Mitsubishi UFJ Merrill Lynch PB Securities Co., Ltd. became a subsidiary of Mitsubishi UFJ Securities Holdings
March	2014	Mitsubishi UFJ Merrill Lynch PB Securities became a subsidiary of Mitsubishi UFJ Morgan Stanley Securities, the subsidiary of Mitsubishi UFJ Securities Holdings, and renamed to Mitsubishi UFJ Morgan Stanley PB Securities Co., Ltd.
April	2015	kabu. com Securities Co., Ltd. (currently Mitsubishi UFJ eSmart Securities Co., Ltd.) became a subsidiary of Mitsubishi UFJ Securities Holdings
July		Mitsubishi UFJ Kokusai Asset Management Co., Ltd. became an equity method affiliated company as a result of merger of Mitsubishi UFJ Asset Management Co., Ltd. (surviving company) and KOKUSAI Asset Management Co., Ltd(extinct company).
August	2020	Mitsubishi UFJ Morgan Stanley Securities merged with and absorbed Mitsubishi UFJ Morgan Stanley PB Securities Co., Ltd.
February	2025	Following the acquisition of Mitsubishi UFJ eSmart Securities as a wholly owned subsidiary by MUFG Bank, Ltd., Mitsubishi UFJ eSmart Securities was excluded from the consolidation scope of Mitsubishi UFJ Securities Holdings Co., Ltd.