H2 (Japanese: エイチ・ツー Hepburn: Eichi Tsū) is a Japanese manga written by Mitsuru Adachi portraying high school baseball. It has been made into an 41-episode anime series and an 11-episode television drama series, H2: Kimi to Ita Hibi, directed by Yukihiko Tsutsumi.
During middle school, Hiro Kunimi (pitcher), Hideo Tachibana (third baseman and 4th batter), and Atsushi Noda (catcher) were friends and teammates on the same baseball team. Thanks to their skills, their school achieved an unbeaten record on their way to consecutive national championships.
In the seventh grade Hiro also played matchmaker to Hideo and Hikari Amamiya, a neighborhood childhood friend who grew up with him as close as a sibling. At this time Hiro, victim of a delayed growth spurt, was a very short, comparatively immature boy, uninterested in girls, and initially happy that he could get the two of them together. Eventually Hiro realized that he too had feelings for Hikari and, once he grew up, Hikari also realized that her affection for Hiro might be something more than sisterly.