Growing up isolated, Kyouko's life takes a surreal turn when she encounters Lucifer, who asserts his princely status from the Underworld. Despite Lucifer's sudden interest in marrying her, Kyouko faces unexpected competition from Ishii-kun, the recipient of her previous affections. As Kyouko navigates these unusual romantic entanglements, she must confront her own feelings and make a choice that could alter her destiny.