Plot: after an accident wrecked Sakai's body, the doctors turned what was left into a cyborg creating a Robostudent. They assumed from his torn photo that he looked like a girl, so they mistakenly turned him into one. (There's more tg than robot fetishism in this one, as he never gets reprogramed or ever talks like a robot.)
Then he goes back to his old school, but he only manages to hide who he was for 2 weeks before his best friend finds out. Like I've come to expect from Japanese "best friends", he threatens to reveal his secret if he doesn't let him fuck him at least once. (Here the writer missed a good chance to have Sakai get revenge with the line, "My friends call me Sakai; you call me Robostudent.") Afterward he plays around, but decides boys fuck better. Next he becomes a slut who fucks geezers he knows from the web, and so it ends. The omake is how he can't help but orgasm during liquid replacement maintainence