Rin is one of Satori's pets, whose job is to carry corpses to the former Hell of Blazing Fires to regulate its heat. Before the events of Subterranean Animism, Rin learned of her old friend Utsuho's newly acquired power, and of her plans to conquer the above ground. She got terrified at the thought of her friend's future, and the punishment her mistress would impart on her (even though Satori would actually never have, and it was just Rin's thinking on her side). She decided to drive the evil spirits to above ground to lure the youkai in and get them to help her, but instead a human appears before her. Upon seeing that human is unexpectedly strong, though, she asks her to help Utsuho.