yea if thats ok with you

Ok so I guess I'm playing as a shogi player, and her mother is still fixing matches.

Oki doki! I just wanted it as an option

I don't really like forced babying and cruel humiliation so I definitely won't have a persona mess with her or anything. Don't even really know how that would work since those personas have to be in the metaverse.

I'd say an alternate one, where it's happened but she hasn't meet any of the phantom thieves (Unless you want to play one of them) and she wasn't roped into Ren's fate, perhaps even being able to use their personas to mess with her if thats your sort of thing

Definitely a more fleshed out idea. Does this take place in a timeline where 5 didn't happen?

Ah yay! well then it could be an oc or any character you want but in a basic sense. Hifumi is training to get better at shogi and eventually attempts to wear diapers to minimize her time away from the board during matches or training. Eventually your Oc/character begins playing shogi with her and after a bit notices her diapers, given her meek personality and social awkardness the oc takes this as an oppurtunity to make her agree to a deal where if they win they can baby her. She looses but instead of just babying her they begin to help her train and relax from the stress of her mother's pressure and the rude comments of her club

Yes, I'm actually doing another rp right now on here staring her.

Oki doki well do you know Hifumi from persona 5/royal she's the shogi confidant and star arcana

I haven't played that one. Skipped it due to it not having the confidants from 5 and characters from 5 Royal.