/ miyacest, nsfw, bestiality, age gap middle school Atsumu sees his dog in heat for the first time, he doesn't understand why is he like that, so 20 y/o Osamu teaches him what it it's and what's what his dog wants. Atsumu ends up being fucked by his dog while Osamu mastubates+

a few weeks later Atsumu is curious about how human sex it's like, so of course Osamu fucks him and let Atsumu fuck him too with his little cock. This goes on for ages, little Tsumu turning into big Tsumu, and little dogs turning into big dogs