While spending a summer break at her grandfather"s home, six‑year‑old Hotaru Takegawa wanders into a forest said to be haunted by spirits. In distress, she cries for help and is met by Gin—a masked boy of enigmatic appearance—who offers his assistance.
Delighted to see someone else, Hotaru rushes toward Gin with open arms, only to be brusquely rebuffed. She soon discovers the serious cause of his harshness: a terrible curse afflicts Gin, and any human touch will erase him forever.
Gin begs her never to return, yet Hotaru does the opposite, and within a short time they form a close friendship despite his fragile predicament. However, as years go by and their affection deepens, Hotaru and Gin confront the limits imposed by fate. Their bond, though tested by unseen forces, remains a testament to courage and hope for years always together.