F by sakamoto, his experience was pure terror
It's really amusing how he got broken so hard.
But it's all on him imo. Instead of being happy about having sex with a cute girl, he's upset about waking up with an old man - to the extent of not having sex with girls anymore.
I mean, he should have looked for someone wanting a ftm and suggesting "I got this thing that seems to transform girls to men, want to try it out?" and go on like a proper protagonist. Instead he has a mob attitude and remains a mob forever. (Which I guess is his role in the manga, so... er, I guess well done that man after all.)