The narrator is suddenly dumped by Luna, the older girlfriend he still loves, after she says she has found someone else. That man turns out to be his best friend, Keita. Then Luna comes to the convenience store where he works and buys XL condoms. He cannot stop imagining Keita's bigger cock making her cum and seeing her suck it with a shameless expression she never showed her ex. Those humiliating fantasies leave him unable to stop getting a miserable erection, even at work.