MrGlitchy1
TL;DR: MHA cast isekaid into Umamusume and Izuku bacomes a trainer
(Umamusume X MHA)
Izuku Midoriya simply wanted to go home, and get a well-deserved break in his All Might memorabilia-filled room after all that has happened. Unfortunately (or fortunately), as fate would have it, he was suddenly dropped into the middle of the Japan Cup.
After the fall of All For One, the world is finally at peace, and Izuku-now quirkless save for a few flickering embers-is ready to start over.
That idea lasted only a few hours after his discharge from the hospital before he, nearly all of U.A., and a handful of top heroes were thrown into a world obsessed with horse girls, racing, and glory.
And it's not just them adjusting. As two worlds collide, injured and old Umamusume find themselves patched up by powers that were never meant for this world-and the track is seeing new faces, albeit with very strange "running" styles.
With no way home, and a fading quirk, Izuku finds a new purpose in something else, something he would never expect. If he can't be the hero anymore, he'd help these girls become the heroes of their own stories.