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.
I’m running on an old biological model- it’s at least 100,000 years out of date. I hear these new silicon models are amazing, but the buy-in of being burnt to a crisp first seems pretty steep.
You either replace the ruined body with machine, or just brainwash the individual to something else. Either plot would make sense. You may even replace an individual with a whole different (robotic) clone for some great evil plan. But you can't just replace the body and keep the brain carefully, then go brainwashing it - that makes no sense. That is just like "upgrading" a laptop (not desktop; not that easily) with new CPU, motherboard, GPU, case, cables/connectors and all other input/output devices, only keeping the old hard drive but formatting it and installing a new system - "upgrading" my ass.