Tokyo East 21, Office skyscraper in Koto, Japan

Tokyo East 21 is an office and hotel skyscraper in Koto featuring workspace across multiple floors and accommodations for guests. The complex also houses numerous dining establishments and meeting facilities designed for both business and leisure visitors.

Tokyo East 21 opened in July 1992, built by the Kajima Corporation group on land in Fukagawa that Kajima had used as an equipment centre before the war. The complex was planned as part of Koto Ward's civic zone, with shopping, hotel, event and office facilities. In 2002 Kajima Tokyo Development absorbed Kajima Hotel Enterprises and took over the hotel's operation directly.

The name East 21 refers to the complex's location in eastern Tokyo and its opening in July 1992. The site had been a machinery centre for Kajima Corporation, which kept its headquarters in Fukagawa before the war. The hotel belongs to the Okura Hotels group and has 404 guest rooms.

The complex sits in the civic zone of Kōtō Ward, with the East 21 Tower rising 21 floors and shops on floors 1 and 2. The East 21 Mall gathers restaurants, a convenience store, ATMs and medical offices such as internal medicine and dentistry. The East 21 Plaza, a planted open space, hosts events and serves as a rest spot for office workers and shoppers.

The site was a machinery centre for Kajima Corporation, whose headquarters stood in Fukagawa before the war; the complex opened in July 1992. In July 2012 Kajima began building a smart energy network across the site, aimed at area-wide energy use and independent power supply.