In high school, Keita Tsukiji was slender and had feminine features. He confessed to an upper-classman who had his ideal body build, Satoshi Murakami, and they started going out.

Three years have passed. The two of them started living together, but there was one big change… Keita had matured and grown to be really manly! Anxious about what Satoshi, who used to be straight, thinks about the situation, Keita is distracted during sex. On the other hand, Satoshi is concerned that he cannot make love to Keita in the same manner that he used to. And then, one night, an aroused Keita pushes Satoshi down…?!