noun
box seat; tatami box seat
A square seating area partitioned by low rails, traditionally on tatami, accommodating about four people. Typical at sumo tournaments, kabuki theaters, and similar traditional venues.
大相撲の升席は、四人で座るのにちょうどいい広さだ。
A box seat at a grand sumo tournament is just the right size for four people to sit together.
歌舞伎の升席を予約した。
I reserved a box seat for the kabuki performance.
Compound of 升 (masu, a square wooden box) and 席 (seki, seat), referring to a square seating area resembling a masu box.