>>4044774Basically the company Shindoh is working for is developing shota sexbots, and he's tasked with doing continuous "tests" on the prototype (Toshio) and teaching him how to behave like a good roboslut. Shindoh originally refuses because he isn't into boys, and even though he ultimately has sex with Toshio he prefers to teach him non-sexual things (like being able to talk, read and write), making Toshio grow incredibly attached to Shindoh while Shindoh develops a different, more paternal, kind of feelings for Toshio.
>>>HUGE SPOILER<<<It's eventually revealed that Toshio is a real boy that was taken from the streets, had his mind wiped out and parts of his body replaced with robotic parts, which is why he needs to be taught about everything like a baby. The company also planned to discard him once the tests were completed, but Shindoh manages to convince the president (his father) to give Toshio to him, where he keeps him as a son.