Haven't tried it myself but discovered this game on Ryuu -
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it is a visual novel. and it has some bad things.
you have a routine of going to school everyday and chatting the girls. ( i did not translate it so i do not know what it was said)
then at night you discover CG of them sucking dicks and getting fucked. then you go back to school and have more conversations while watching their naked pictures.
not very interesting and quite focused on the fetish. of oooo normal conversation but you actually have sex lol. my guess is that you find a pick of them getting fucked and they talk about going to the park and you are with the picture in the hand that proves they were getting railed.
the routine was anoying because it involved loading and transitions that were unskippable. (i got tired of taking the train wich was a 5 second loading screen. (3 secs blooming up 2 secs static image 3 secs dimming down)