1890	March	Mitsubishi Company purchased two properties disposed of by the government: Marunouchi Military Land used by the Department of War and the Kanda Misakicho Troop Training Grounds.
	September	The Marunouchi Architectural Office established (The origin of Mitsubishi Jisho Sekkei Inc.).

1893	December	Mitsubishi Goshi Kaisha (The Mitsubishi Company) was established.
1894	June	Mitsubishi No.1 Building completed, the first office building in the Marunouchi district.
1906	July	The Real Estate Division established within Mitsubishi Goshi Kaisha.
1923	February	Marunouchi Building completed.

1937	May	Mitsubishi Estate Co., Ltd. established with a capitalization of \15 million. Mitsubishi Goshi Kaisha transfers to the new company ownership of the Marunouchi Building and surrounding land, as well as operating rights for other company land and buildings located in the Marunouchi district.
	November	Mitsubishi Estate takes over all business operations from the Construction Division of Mitsubishi Goshi Kaisha.
1959	July	Marunouchi Remodeling Plan formulated.
1972	June	Phase 1 of Izumi Park Town begun.
1987	February	Hiroo Garden Hills completed.
1988	January	Yokohama Minato Mirai 21, a Block 25 development plan, announced.
1993	July	Yokohama Landmark Tower completed.
1996	November	Main office moved to the Tokyo Building.
1999	March	Architectural Design & Engineering Division acquires ISO9001 certification for quality management.
2000	April	Organizational restructuring implemented (including the introduction of a "business group" system that integrates all affiliated companies).

2001	March	Mitsubishi Jisho Sekkei Inc. established.
	June	Mitsubishi Jisho Sekkei Inc. formerly the Design Management Division of Mitsubishi Estate, begins operating as a separate company.
2002	January	Mitsubishi Jisho Sekkei Inc. acquires ISO14001 certification for environmental management.
	August	Reconstruction of the Marunouchi Building completed.
2003	February	Main office moved to the Fuji Building.
	April	Business cooperation with East China Architectural Design & Research Institute Co., Ltd.
2004	November	Osaka Security Market Office Building completed.
2005	August	Meiji Yasuda Seimei Building completed.
2006	March	Mitsubishi Shoji Building completed.
2007	March	Partnership with K.ITO Architects & Engineers Inc. concluded.
	April	Shin Marunouchi Building completed.
	May	The Peninsula Tokyo completed.
	October	Shanghai Office established. Yurakucho ITOCiA completed.
2008	July	Breeze Tower completed.
2009	April	Otemach 1-Chome Project completed. Marunouchi park Building & Mitsubishi Ichigokan completed.
2011	July	Mitsubishi Jisho Sekkei Architectural & Engineering Design(Shanghai) Co., Ltd. established.