My mother (Maki) and I have been living together since my father passed away when I was young. To attend the same university he did, I started taking lessons this spring from our tutor, Sugihara. He's smart, tall, and handsome—the kind of guy any college student would look up to. But whenever Mom mentioned him, she changed her attitude completely, almost like she saw him as prey. It was unsettling how she could switch between seeing him as a respectable teacher and someone dangerous. And then one day during his break, I caught them fixing their clothes together...

早くに父を亡くした僕は母（麻妃）と二入で暮らしている。父と同じ大学に入る為、この春から家庭教師・杉浦さんに勉強を見てもらっている。頭が良くて、身長も高く、イケメン大学生…僕にとっては憧れの存在だったが母の話になると態度が急変し、獲物を狙う様な目をするのが怖かった。母を女性として意識する僕にとって危険な存在。そして家庭教師の仕事が休みの日、乱れた衣服を直す母と杉浦さんを目撃してしまって…。