Ohniwa Tōko, a woman who uses a wheelchair, hails from a wealthy family renowned for cultivating rare orchids. She lives in isolation with her brother, Kaname Ōba, guarding a sinister legacy: their father murdered Tōko’s lover—a household servant—with a bow and arrow, then perpetuated killings over decades, cremating victims to fertilize the family’s orchids. Tōko and Kaname, bound by complicity, sustained this ritual, their flowers flourishing on human ashes.

Despite her physical limitations, Tōko upholds the family’s veneer of respectability, submitting prize-winning orchids to competitions while obscuring their grotesque origins. Her bond with Kaname intertwines loyalty, guilt, and devotion to their father’s macabre legacy. When their secret unravels, the siblings confront the psychological decay bred by years of concealment, exposing a tragedy steeped in vengeance and the warped symbiosis between beauty and death.