On a rainy day, Takiyuki Aida meets a boy with snake hair named Yohira. The two begin living together at the Aida Leather Workshop, but there is "Something" about Takiyuki and Yohira that must never be touched—— The anomalous atmosphere spreading through Nawami Town where they live, the mysterious Mark, the past of the Aida family, and just "who" is this snake-haired boy really?