This is (a re-up of) a porn-with-plot story I did on Pixiv before I had to remove it due to issues with uncensored genitals.
This story is basically me giving the middle finger to Reiji Miyajima, his "Kanojo, Okarishimasu" series; and the idea that it's acceptable for a shounen lead should be weak, cuckable, a punching bag, and receive no sex (except in his fantasies). I wanna destroy that way of thinking. However; my story turned an illustrative universe of crossovers and what-ifs. I was having way too much fun with it to stop.
My stories spanded 2 "seasons," a "movie," a "spin-off," and a third season that's left incomplete after getting warned by Pixiv. My hope is that you're able to enjoy my alternate universe's Kazuya; as well as everyone else.
You can find my Koikatsu cards over at db.bepis.moe.