Taiyou ga Ippai

Mei is a twelfth grader in an escalator school system. She has a crush on her upperclassman Takaoka; meanwhile, she has been annoyed by the pursuit of an eighth grader named Masami. However, at almost the same time she has found out that Takaoka already has a girlfriend while Masami has started to show impatience and begins to distance himself from her because being refused repeatedly, she suddenly realizes that her crush on Takaoka is merely an admiration and she has already fall in love with Masami.

(Source: AnimeNewsNetwork)