Gin, abandoned as an infant in the mountains, survives through the Mountain God’s spell—slowing his aging to a quarter-human speed but cursing him to disintegrate upon physical contact with people. Raised by forest spirits, he wears a yokai mask to blend among them, shedding it incrementally around Hotaru, a human girl he meets during her annual summer visits. His isolation molds a demeanor both gently serene and achingly naive, softened only by cautious trust in their evolving bond.

Their friendship deepens into mutual romance as Hotaru ages and Gin remains unchanged, their longing strained by his curse. During a yokai festival, accidental contact with a human child triggers his disintegration. He chooses to embrace Hotaru one final time, dissolving into the air and leaving his mask as her sole keepsake.

Between their meetings, Gin’s quiet yearning manifests in small, doomed gestures: preserving a persimmon in mountain ice to gift Hotaru after a shared pudding, only for a lost spirit to devour it. The forest yokai, his adoptive guardians, enforce his curse’s boundaries, anchoring him in a twilight existence—neither human nor spirit, forever suspended between worlds by magic and loss.