Thinking of a Yuu who's so RSA-like and loves singing and twirling and dancing like a D*sney princess,,,
I constantly think of Yuu cleaning up Ramshackle whilst prancing around and singing.
Maybe sometimes they sing lullabies to Grim if he's having trouble sleeping and maybe they have the ghosts singing wiith them too.
This musical Yuu doesn't want to forget the lyrics so they wrote them all down the second they get a chance to rest.
Or maybe they know how to play an instrument and introduce otherworldly songs to their friends.
What if they set up a music account with only vocals of the songs they remember (with due credit of course) and they let random people produce the backing track. (Not even in twst, but I think that concept would be kinda cool, an artist releasing only vocals and the media can make their own versions of it)
But back to 'princess' Yuu, they keep beieving they can find a happy ending for themselves and the people around tem despite the hardships.
They'd probably get bullied, wouldn't they? By the background characters n shit, just because they act like the stereotypical RSA student. But some people in the main cast would be weirdly unsettled by the positivity this Yuu exuberates.
I can imagine this Yuu just creating their own choreography or they're like those people who burst out into song as soon as a random word is said except, in true D*sney fashion, they get their own music behind them. They dance around pillar reminiscent sturctures and run through the greenery surrounding Ramshackle like it's a hill.
I've gotten most inspiraton from Maria in The Sound Of Music and disney princesses lol,,,
They'd just be so whimsical and daydreamy and sing songy and somehow be so lucky and unlucky at the same time.