セガサミーホールディングス
Sega and its parent company Sega Sammy Holdings, best known for its "Sonic the Hedgehog" franchise, was originally headquartered in Ota. However, Sega Sammy Holdings announced in April 2017 that it would relocate its head office functions and domestic subsidiaries to Shinagawa-ku by January 2018. This was to consolidate scattered head office functions including Sega Sammy Holdings, Sammy Corporation, Sega Holdings, Sega Games, Atlus, Sammy Network, and Dartslive. After the relocation to Shinagawa-ku was complete, Sega's previous headquarters in Ōta was later sold in February 2019 and will likely be torn down.