Green Window

MARS (マルス, Marusu^?), which stands for Multi Access seat Reservation System, is a train ticket reservation system used by the railway companies of former Japanese National Railways, currently Japan Railways Group (JR Group) and travel agencies in Japan.

The host of the system is located in Kokubunji, Tokyo and managed by Railway Information Systems Co., Ltd. (JR Systems), a JR Group company jointly owned by the seven members of the group.

Ticket offices at JR stations equipped with MARS terminals are called Midori no Madoguchi (みどりの窓口^?, literally "green window"), selling tickets for all JR Group trains with reserved seats beginning one month prior to the ride.

A Midori no Madoguchi ticket office at Himeji Station in 2009

A MARS-101 terminal as used in the 1960s

...
Wikipedia