Anzu has just moved to a new town during Obon, a time for families to remember and celebrate their ancestors. Ever since her obaachan died, though, Obon has lost its magic. She doesn't feel much like celebrating anymore.

While avoiding holiday festivities, Anzu spots a stray dog down the street. A dog that seems to be staring right at her. But when she chases after it, she slips and falls down a ridge, losing consciousness. When she awakes, she's in the Shinto underworld known as Yomi, a place she's only heard about in Obaachan's stories. The stray dog, she finds out, is actually the Gatekeeper of Yomi, and he warns her to return to the human realm before it's too late.

Only, getting home is not as simple as she'd thought. Faced with the nefarious Queen Izanami of Yomi and a world full of creatures she'd once thought weren't real, the race against the clock is on. She must break a curse, free the spirits of other lost children, and reach the gate home before sunrise...or be stuck in Yomi forever.