A girl is born with a single lump on her body. Her father calls her Kobu, meaning lump, and she is bullied relentlessly because of it. Eventually she stops attending school and spends her days in lonely isolation. Then one day, lumps begin to sprout all over her body, covering her from head to toe. This transformation triggers a descent into a grotesque and terrifying new reality, where her own flesh becomes both a prison and a source of unimaginable horror.

The story is the central entry in a one-volume collection of six horror shorts by Hideshi Hino. Other tales in the volume include Tenkousei (Transfer Student), Shiryou no Umi (Sea of Ghosts), Occult Play, 3737 no Nazo (The 3737 Mystery), and Sei Shiko no Yoru. Each story explores themes of bodily decay, social ostracism, and the supernatural, set in a bleak and often surreal atmosphere typical of Hino’s brand of visceral horror. The unnamed protagonist of the title story is the only recurring character, and her journey from isolated outcast to monstrous entity forms the core narrative arc.