One: Kagayaku Kisetsu e
Genres: Drama, Supernatural
Type: OVA, Episodes: 4
Aired: Aug 10, 2001 to May 24, 2002
Studio: Arms
Source: Visual novel
Rating: PG-13 - Teens 13 or older
Synopsis:
Orihara Kouhei returns to his town after a long disappearance to fullfil the promises he made to several girls in his childhood. He suffered from memory loss, and carries a tragic past. An strange ambience surrounds the OVA...It's almost like a dream, like memories from the past trying to come together in one piece but without being able to...

(Source: ANN)