The Kantetsu Green Bus Co., Ltd. is a bus company within the Kanto Railway, and also belongs to Keisei Group. The company was established on 15 March 2002 to inherit the partial business of the Kanto Railway's bus department.

The Tokyo BRT (東京BRT) is a bus rapid transit system operated by Keisei Bus that was established on 8 July 2019. Tokyo BRT buses are parked at a building owned by Tokyo BRT and located in Shinonome, Kōtō. The network's two bases—Okuto Office and Shinonome Barn—are also used by Keisei Bus.