The JR ticket office at stations where you can buy, change, or refund tickets, and reserve seats; commonly called 'Midori no Madoguchi' (Green Ticket Window).
新幹線の指定席を買うために、みどりの窓口に並んだ。
I lined up at the JR ticket office to buy a reserved seat on the Shinkansen.
みどりの窓口は駅の営業時間内に利用できるが、混雑することが多い。
The ticket office is available during station hours, but it is often crowded.
オンラインで取れない切符は、みどりの窓口で相談すると対応してくれることがある。
Tickets that cannot be obtained online can sometimes be handled if you consult the staff at the ticket office.