also: マス・ゲーム
noun
mass calisthenics; mass gymnastics; group display
Wasei-eigo term for large-scale, synchronized group exercises or performances, often seen at sports days or national events.
wasei-eigo (Japanese-coined English), from mass game
運動会で全校生徒によるマスゲームが披露された。
A mass calisthenics performance by all the students was presented at the sports day.
北
North Korea's mass games are world-famous.