this is a fleeting and lewd sexual experience that happened 20 years ago... seichi, who was entrusted to the home of kana, his mother's cousin, because of his mother's hospitalization. what awaited him, who was delighted with his life with his beautiful cousin, was a scene that was too stimulating for a child's heart. kana, who is masturbating in the middle of the night, and secret sexual treatment of her own son... seichi, who was of age, couldn't suppress his impulse and sought kana's body. kana, who was also frustrated, gradually responded, and the two developed into a forbidden relationship...