Kanon's stepfather gradually develops sexual feelings for her, his wife's daughter from a previous relationship, drawing closer through everyday conversations and light physical contact. Noticing Kanon's timid nature and lack of resistance, he takes advantage of her vulnerability to deepen their relationship. One day, learning his wife is away on a night shift and that Kanon is home sick from school, he decides to visit her in her room. The fateful day has arrived—his hands reach out toward her delicate, soft body.