also: しょじつ
noun, adverb
Refers to the first day of an event, performance, exhibition, or similar occasion. Often used for sumo tournaments, theater runs, and movie releases.
大相撲初日は満員御礼だった。
The first day of the grand sumo tournament was a full house.
映画の初日舞台挨拶に行った。
I went to the opening-day stage greeting for the movie.