Hikaru ga Chikyuu ni Ita koro......

A high school student named Koremitsu Akagi attends the funeral of Hikaru Mikado, who died during Golden Week. He barely knew Hikaru, yet he is there for reasons unclear. Hikaru, now a ghost, returns to fulfill a promise to his fiancée, Aoi Saotome. Only Koremitsu can see him, and Hikaru asks him to help complete the promise. Koremitsu agrees and attempts to fulfill Hikaru's other commitments to his "girlfriends," helping them resolve past issues and mend relationships. However, the circumstances of Hikaru's death remain uncertain, as it is unclear whether it was truly an accident.