Huh, this game. I played it a while back in Japanese, it wasn't really too hard to understand then either since I assume the plot is mostly just one big excuse for the fucking machines to be there. The gameplay loop basically wants you to meet quotas for training and if you fuck up its not much of a big deal since you keep upgrades anyway.
That said, yeah, the game is entirely only fucking machines. Not even the MC gets to put it in but there's probably some plot excuse for it that I didn't know at the time since I can't read Japanese. Doesn't mean there isn't any penetration though but I wish they at least ripped or took off Mirai's suit for some of the scenes but hey, there's people out there that are into these kind of suits and would like to fuck a girl through the latex or whatever material its made out of.