Kohaku is a rather accident-prone angel who has come to Earth in search of the Angel Master, Hisui. After getting trapped in a tree and attacked by a crow, Kohaku is rescued by Shuichirou, a young doctor. As a result, Kohaku feels indebted to grant him one wish but finds the kind doctor is satisfied with all aspects of his life. Thus, Kohaku remains with Shuichirou in hopes of repaying him somehow (subsequently getting in other sticky situations as a result).

Wish spoilers

Kobato spoilers

In the anime series, Kohaku is introduced early in the series and befriends Kobato. Because Ioryogi is aware of Kohaku's true nature, he constantly asks Kohaku if there's something they can do to change Kobato's wish, though Kohaku's response is always that there's nothing to do. At the end of the series, it is Kohaku who explains to Fujimoto the nature of Kobato's wish and assures the young man that if they are fated to be together they will be in time.<!--spoiler-->

Drug&amp;Drop spoilers

(Source: Wikipedia)