Itsu made mo Musuko no Mama ja Irarenai! | いつまでも息子のままじゃいられない！ ～巨乳で美人な母さんは家では無防備すぎて僕の股間はもう限界！～

The protagonist, Subaru, has been in love with his mother for a long time. While trying to hide these deplorable feelings, one day, he accidently pushes her down.

However, she agrees to be his lover until he gets a girlfriend. And so, the journey trying to become a real lover with his mother begins.