Naisho no Tsubomi
English name: Naisho no Tsubomi
Genres: Romance
Type: OVA, Episodes: 3
Aired: Apr 25, 2008 to Jun 27, 2008
Studio: Studio Kikan
Source: Manga
Rating: PG - Children
Synopsis:
Tsubomi Tachibana is a fifth grader dealing with rather sensitive issues such as her mother's pregnancy, her first period and the strange feelings she has started to get when she has been around boys.

(Source: ANN)