Wakeari Kusushi no Yorozu Hoechiyou
ワケあり薬師の万覚帳
Kohaku is a pharmacist employed at the drugstore Seishindo, where he regularly gathers herbs alongside his companion, a snake named Hakkaku. During one such outing, Kohaku is attacked by a spirit that preys on humans, sustaining a severe injury to his chest. Just as the spirit is about to consume his heart, Hakkaku intervenes, transforming into a human and rescuing Kohaku.