Sahoko and Rio, two classmates, find solace in each other's company despite their tumultuous pasts. Rio suffers from depression and self-inflicted harm, and her family (comprising of her father, stepmother, and stepbrother) doesn't show her any love. However, Sahoko brings some light into her life. Sahoko herself has a cryptic backstory and doesn't share a good rapport with her parents as she lives with her aunt. Moreover, there's a suggestion that Sahoko and Rio have met before when they were much younger.
