The Niiyama family used to be very happy until a major incident occurred, when their father suddenly passed away in an accident, leaving the two mother and child to take care of each other. Not long after, Ms. Niiyama remarried because she could not bear the burden alone; it is necessary to have a man as a strong pillar in the family for life to become easier. The time before her stepfather arrived was filled with emotional deprivation for the two of them, which is why Niiyama easily fell for her stepfather due to his caring and gentle actions. During one incident when they were bathing together, she could not hold back her intense sexual desire in front of him; he, understanding the psychology of girls, did not hesitate to assist in relieving the psychological needs of a young girl in her adolescence.