The first appearance or debut of a work, person, product, etc.; used when something is introduced publicly for the first time.
新キャラクターが今週号の漫画で初登場した。
The new character made its first appearance in this week's issue of the manga.
その商品は秋の展示会で初登場する予定だ。
That product is scheduled to debut at the autumn exhibition.
俳優は映画祭で主演作が初登場したとき、大きな注目を浴びた。
When the actor's leading film debuted at the festival, he attracted a lot of attention.