Kouta and Yousuke, who were once friends in high school, drifted apart after a certain incident. They're reunited when Yousuke invites Kouta to stay with him at a Western-style holiday home deep in the forest. After they arrive, they discover other people were lured there, and find themselves trapped inside. The only escape seems to be to confess their sins.
Taku, a first-year student of senior high school, living in Nasu, Tochigi Prefecture, witnesses a man trying to jump from a bridge. He instinctively stops the man and the two get talking. He finds out the man's name is Mitsuru and brings him home with him. With no place to stay the night, Taku allows Mitsuru to stay in his home. However, what he could never expect is that Mitsuru is a friend of his late brother who tragically died.