In the summer of 1996, in a small seaside town in Kumamoto, a mysterious divine light known as Shiranui appears, said to have the power to grant a single wish. The story centers on Minato, a lonely 10-year-old boy neglected by his alcoholic father. Finding no solace at home, he spends his days by the water, where his only comfort comes from Ben-chan, a young girl who is the deity of Benten Island.

As Minato faces the upheaval of being sent to an orphanage and the painful prospect of parting with Ben-chan, he places his hope in the Shiranui light and makes a wish on her behalf. However, the circumstances of his life cause the deep-seated hatred he harbors toward his father to fester. This negative emotion gradually corrupts the pure wish, transforming it into a malicious curse directed against his own parent. The film follows how a child's desire to protect a precious connection becomes tragically entangled with familial resentment, exploring the fine line between hope and hatred.