On her way cycling to school, a long-haired stranger stops Suzume to ask if there were ruins nearby. After letting him know, she suddenly has a feeling they've met before and decides to follow after him to the ruins. She doesn't find her there but instead, she finds a white door and decides to open it. A strange place appears but nothing...

Denji's father left behind a large debt and despite selling off his organs he still has a lot to pay back and barely has enough to feed himself. Perhaps fortunately for him, an injured little Devil named Pochita was nearby the day his father passed away and after allowing it to feed on his blood to heal, they're now partners...