His wife died early, because he wanted his son to enjoy full love from his parents, so the father decided to take another step. But his new wife was an extremely lewd woman and this greatly affected his adult son. After many nights of constantly hearing moans in his parents' bedroom, his cock was curious to snoop and discovered that the sex scene was happening right in front of his eyes. Since that day, the lewd stepmother Mako Oda has acted extremely unusually towards him, extremely provocative and sensual actions. Probably because he was discovered by his stepmother when he peeked that night. But all of that also makes him extremely excited, when his father goes out is also a good time for mother and daughter to have a comfortable private time doing what they are desiring, including incest.