Naisho no Tsubomi
7.24 / 10 on MyAnimeList
Comedy · Drama · Romance · Slice of Life · Supernatural
Each volume depicts a different heroine. Volume 1: Main character of the story is Tachibana Tsubomi (立花つぼみ), a fifth grader dealing with issues such as her mother's pregnancy, her first period, and the strange feelings… Synopsis via AniList