The story
Founded by Isao Okawa on Oct 25, 1969.1
In 1969, Sumitomo Computer Service Corporation was established by Sumitomo Corporation. In 2005, Sumitomo Computer Service Corporation and Sumitomo Electronics Corporation were merged into Sumitomo Computer System Corporation.
Separately, in 1968, CSK Corporation was established by Japanese entrepreneur Isao Okawa in 1968. The acronym CSK was derived from "Computer Service". CSK established CSK Research Institute, later renamed as CRI Middleware, in 1983. At its peak, the company, the largest independent software company in Japan until it being acquired, was called the CSK Group. In the 2000s, its real estate investment business failed, resulting in heavy losses to the company after Okawa's death in 2001.
Outside of Japan, CSK was widely known for its takeover of Sega in 1984, ended in the sale of the company to Sammy in 2004, through which Sega Sammy Holdings was established.
In April 2011, Sumitomo Corporation acquired CSK through a takeover. In October 2011, Sumitomo Computer System Corporation and CSK Corporation went through a statutory merger, in which Sumitomo Computer System absorbed CSK Corporation and was re-branded SCSK Corporation.
At the 2025 Japan Mobility Show, SCSK unveiled a new electric concept car that leans heavily on emerging artificial intelligence technology to create a personalized experience for each driver. The company claims the car to a software-defined vehicle, wherein the emphasis upon customization is within updatable software as compared to rigid hardware.
SCSK was delisted from the Tokyo Stock Exchange in February 2026.
From Wikipedia’s article on SCSK, shared under CC BY-SA 4.0.6