The first summer vacation after I enrolled in Shinhoku Academy… My mother got pregnant with my best friend's child.

"Aah, ah, yes, Nagi-kun! More intensely, knock the entrance of my womb full with your penis!"

In front of me, my mother Nishino Riho, is being held by my best friend Terashima Nagi. My sweet, beloved mother is moaning, emitting lewd sounds unlike anything I could have ever imagined, and being sexually pleasured by my friend, Nagi's, young penis. Why? How did this happen? When did my mother and Nagi become involved in a sexual relationship? Why is Mom pregnant with Nagi's baby and not Dad's? I don't understand anything. No, I don't want to understand. Overwhelmed by despair, I watch helplessly as Nagi thrusts into Mom with such force. I've lost my beloved mother, the person I love more than anyone, to Nagi. My mother's kind eyes no longer look at me. They only see Nagi. I can't forgive Nagi for having sex with my mother and getting her pregnant without my knowledge! But Mom doesn't seem to mind. In fact, she's wearing a look of ecstasy I've never seen before, accepting Nagi's penis. Anger, hatred, despair... a mix of emotions flood through me, yet I'm violently aroused by the sight of my best friend having sex with my mother and my penis is hard.