The first CG you're missing (the one on the middle row, right column) is Haato and Tocchan kissing. I think the only requirement there is to kiss Tocchan three consecutive times during foreplay mode. The one below that is Tocchan in shibari. It's funny, because I honestly put him in binding at random and got the CG. From my playthrough, Tocchan was a sub bottom and it's the second time I used the rope on him. Idk if any of those are requirements/the only requirements tho.
EDIT: I just got the last CG: it's the agency sex scene but with Haato as the top and Tocchan as the bottom. I think Tocchan has to prefer to bottom (I don't think he has to be a sub bc in my current playthrough he's a dom). ^^
Hope this helps. :)