In 2022, the first Green Cars were introduced to the E233 series on the Chuo Line to improve seating service. Unlike conventional double-decker Green Cars, these new cars featured side, double-opening doors to speed up boarding and alighting times. After trial runs, from October 2024, these Green Cars began to be incorporated into regular service trains, forming 12-car sets with the addition of two new Green Cars to the existing 10-car regular trains. Full incorporation into all 58 train sets was completed by March 2025, marking the official start of Green Car service.