Des:Koichi is disturbed by his mother Yuris singing voice leaking from his parents bedroom. He was aware that his parents were planning to have a child. From his sons perspective, this may be something to celebrate. However, when he learns that Yuri has a lewd side that he has never touched, an uncontrollable emotion wells up within Koichi. Its his jealousy towards his father. And possessiveness that wants to have all of Yuri for himself. When his feelings reach their limit, Koichis twisted love for Yuri crosses the line of prohibition.