The 10-car trains will enter passenger service in September and will be used on a new limited express service from Spring 2018.
The 1372mm-gauge 1.5kV dc EMUs feature rotating seats, which can be arranged longitudinally for normal daytime operations or in a forward-facing 2+2 configuration for reserved-seat evening commuter services from Shinjuku to Keio Hachioji and Hashimoto.
The trains are equipped with LED lighting, LCD passenger information screens, free Wi-Fi, and at-seat power-sockets. Each vehicle has a multi-functional area for wheelchairs and pushchairs.
The regenerative braking system supplies charge to a bank of batteries, which can be used to provide traction power for limited operation without current from the overhead catenary.