Yu Takahara

Hiroko attends the memorial service of her fiancé, Itsuki Fujii, who died in a mountain-climbing incident. Although Itsuki's mother says that their old house is gone, Hiroko records the address listed under his name in his yearbook and sends him a letter. Surprisingly, she receives a reply, and discovers it came from his old classmate, a girl who also happens to be called Itsuki Fujii.

A young man who showed little promise while a high school student becomes a master detective, just like his grandfather.