One day, a young man is found unconscious outside the shared household where Ayato lives. Despite the warnings of one of his housemates, Ayato lets this person live with them temporarily. It turns out that the young man is Ryou, who used to be Ayato's childhood friend back when he was two years old. They had been separated eleven years ago, but are now reunited.

Ayato, filled with happiness as he reminisces about their early memories, is gradually drawn to Ryou. However, Ryou appears to be glum with melancholy, as if he's hiding something important...?!