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！ – 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.