They have a pretty singing voice but kinda shy, only ever sing in groups or follow sing-alongs.
Yuu loves to sing or hum to themselves when they know they're alone, like cleaning or taking a walk outside Ramshackle (after Malleus has left). They don't even sing around Grim (but he has caught Yuu singing a couple times).
They always get a song stuck in their head from their home world but realize their music doesn't exist in TW. So Yuu will write down the lyrics when they get stuck in their head. They'll even try to sing a voice memo of their favorite songs to make sure they don't forget it. They have a pretty good memory but don't always get it right, which makes them sadder
Singing Online
Grim thinks his hench-human is super good and should share their talent to get (both of them) famous. He secretly records their singing voice when Yuu thinks he's napping, before posting the shaky clips online.
Yuu finds out and is equal parts annoyed and embarassed. It doesn't get too many views but the few comments are pretty positive at least. They tentatively end up going along with it but on their own terms. They don't show their face still but the sound quality is better and they sing the full songs.
They start off with doing slower ballad-y songs a capella before working up the courage to do more upbeat or fast songs. Grim even finds an old, working acoustic guitar in one of Ramshackle's junk rooms. Yuu brushes up on their guitar skills and eventually do acoustic covers with their face out of frame. They end up having a lot of fun singing online, it also helps them get songs un-stuck in their head
Online Attention
Despite the account saying they do "covers," these songs don't exist in TW and people think Yuu's an up-and-coming songwriter. They don't get super popular overnight but do get some decent positive attention online. Maybe one or two NRC boys may have heard about it.
As someone constantly on social media, Cater is one of those people. He likes their voice fine enough and one specific song captures his attention. He thinks their music is underrated and tries to recommend it to others online.
Some people even start requesting songs, helping Yuu learn more music native to TW. They do a couple of requests of whatever's popular, or sing songs Adeuce made them listened to a couple times (the boys don't know about the account).
Karaoke Night
Speaking of their friends, the first years like to hang out at Ramshackle with game nights and sleepovers. At the end of one sleepover, someone suggests they do karaoke and everyone gets super into it, even Jack. They hand pick a few karaoke songs before putting in on autoplay. Epel and Ortho lowkey try to peer pressure Yuu into doing one of the songs with them or alone. Grim insists they're really good but stops before he accidentally reveals their covers, remembering how upset Yuu got at him. Eventually, they agree to do a song with Sebek and Ace, knowing the two will be loud or showy enough for Yuu to blend in.
As the night winds to an end, the first years start to calm down as they sing more slow songs and start falling into a deep sleep one-by-one. With Ramshackle left awake, Yuu quietly sings one last karaoke song. The soft melody puts Grim to sleep before Yuu turns it off, cleans up, and goes to bed too.
VDC
Yuu is definitely getting more confident in themselves after posting online but never even consider trying to join VDC. They're much more satisfied helping Grim and Adeuce with their audition.
They get Piece of My World stuck in their head and end up singing it a lot on their own (but not doing a cover). Yuu makes a lighthearted joke about their practice only for Deuce to say it's harder than it looks. Simiarly, Ace taunts them into giving it a try. Yuu, rising to the bait, sings the audition piece pretty well before getting embarassed after. Ace backs off after that and Deuce compliments them, surprised.
When the VDC practice is held at Ramshackle, Yuu can't record any songs so they get songs stuck in their head a lot longer. The most frequent one is, unsurprisingly, Absolutely Beautiful. Rookvil catch them singing it late at night, complimenting it and asking why they didn't audition. Yuu explains that they're kinda shy and don't dance too well. The boys sigh and accept it but sometimes ask for help giving pointers to the others.
Yuu waits a little until after VDC before posting an acoustic cover of Absolutely Beautiful, claiming they first heard it at the event. However, this accidentally provides a hint to the NRC boys about the singer's identity.
Toymaker!Yuu: *brushing through Singer!Yuu's hair while sitting in the quad* You need to stop letting people touch your hair.
Singer!Yuu: It was an accident with wind magic. I couldn't help it.(´TωT`)
Toymaker!Yuu: Tell them to stop using magic recklessly around you. Its rude. Now then let's do twin scorpion pigtails so it doesn't get loose while out in the field.
Singer!Yuu: Can we use ribbons in it too?o(^o^)o
Toymaker!Yuu: Yes, yes now stop moving.
RSA Student: Hey, Changling! You and the other Hollow hanging out?
Toymaker!Yuu: What the fuck did you just say?!
Singer!Yuu: Relax, it's just a nickname they gave me.(*^ー^)ノ♪
Toymaker!yuu: He what?! Listen here get the fuck away from us before I hurt you!
RSA Student:*walks away* Whatever you fucking Hollow.
Singer!Yuu: What's going on?(@_@;)
Toymaker!Yuu: He's not your friend. He was mocking you. He was calling you a slur.
Singer!Yuu: Changling is a slur?(◎-◎;)
Toymaker!Yuu: Don’t repeat it. It's a bad word.
Singer!Yuu: And the thing we called you just now? :-(
Toymaker!Yuu: *pinching singer!Yuu's cheeks* Its derogatory. Don't use it either. Remember what I told you, these people can't be trusted. You need to be more cautious! Tell me who else has been calling you that!
Ambrose: Have you been getting along with the other Denizens?
Singer!Yuu: They have been pretty resistant with me. Im still not really sure what a Denizen is. Im not even sure I am one.
Ambrose: Don’t you worry about that. As long as they recognize you as one that's all that matters. It takes time to make friends and they will warm up to you. That's why you were chosen, right? Who can resist your charms?
Singer!Yuu: That's the thing. I think i just need people who are actually similar to me. The others mentioned that their dorm in NRC has so many more Denizens that I think I might find my kind of people with similar hobbies. This IS an exchange program so I think I should go there.
Ambrose: No, Im sorry but that's not possible. I built this program with you in mind. So that you would have allies among your kind but Night Raven College is a dangerous place. The students are a bit misguided but the Headmage is not a trustworthy man. Haven't you ever wondered by so many Denizens attend a magic school?
Singer!Yuu: I don't really know anything about anything. I'm a bit lost on this.
Ambrose: Well to be frank, I want this program to show Denizens that our school welcomes them and will protect them. I hope that those Denizens at that school will transfer here now that they are given the option. It's for their own sake, the forces that their Headmage are influenced by will only spell danger to them.
Singer!Yuu: That's awful. I don't want any one to get hurt. Do you think I can convince them to stay?
Ambrose: You are a kind and generous child, a model student. I'm sure you can do anything you put your mind to. But first you need to befriend them. As long as you continue as you are you will accomplish your goal.
Singer!Yuu: Thank you, Headmage. I will try my best!(*^^*)
Singer!Yuu: Everyone, I have an announcement. I know some here haven't given the warmest welcome to our guests from Night Raven College. That is not what we do, we must be better and strive to bring them into our community here.
Neige: Has someone been harassing them?
Singer!Yuu: I don't know. But they have been so closed off I fear they might be afraid of us. From what I hear NRC is rather hostile. They need a gentle touch.
Lucian: I thought I was very welcoming. I'll have to try harder. Perhaps i could invite the lovely tailor there to dinner.
Neige: Sorry Lucy, but I thenk they are too busy for that. They are coming to set with me and we wouldn't want them to be too tired.
Lucian: I'll come too. Two hands are better then one.
Che'nya: Honestly, I think they aren't scared at all. That serious one could skin you with a glare.
Rielle: That Orca doesn't seem too shy. They are very good at gathering trinkets for me.
Minejael: To be honest, we should just give them space. No need to get in their faces.