Kyouko's existence has been characterized by solitude. Her parents' hectic routines and lack of friends have frequently left her alone. However, one day, while strolling in a garden, she encounters Lucifer, the purported Prince of the Underworld. After saving him, Lucifer vows to make Kyouko his wife. Nonetheless, Ishii-kun, to whom Kyouko had already confessed her affection, now reveals his interest in her. What is the reason for his sudden attraction to her?