KP and TT have been done to death, tbh. So has Naruto and Star Wars (though most of both Star Wars and KP have been flops.). I actually haven't seen a One Piece trainer, and I know the girls are cute as much as I hate mainstream shounen anime. Theres like 2-3 KP trainers, 5 or so TT games including one just started by MUPLUR, the other successful Korra dude. Around 5 Naruto too, and 5-10 Star Wars games though only Orange Trainer stands out at all. Can't speak for Dragon Prince.
Also, I heard MITY isn't a big shounen guy either, I think I read that he hates Naruto and One Piece. He could do Danny Phantom, because it's apparent by now GZone isn't, lel. I mean, just following the whole Nickelodeon vein for a second-- Fairly OddParents? Enough girls there, though?
Back to anime. Dragon Ball's been overdone. What about Bleach?
I mean, Fate/ originally WAS an eroge, but Fate/ could be fun to do. I'd love to train Saber, and Rin. Proud, Moralistic, overly-rigid knight and Snooty, Arrogant Know-it-all mage. They'd both be fun for a slave route, as it'd be fun to tease Saber and show her that she's a girl, on top of a knight-king, and Rin's airheaded tsun is always cute. Not to mention with side series like Fate/Extra, Fate/Apocrypha, Fate/Grand Order, the girl possibilities are practically endless.