Updated Yuu chart~
Lover:
Yuu and Floyd was a surprise relationship that no one in NRC understands how it happened, unless you're Jade and Azul who saw it coming a mile away. They got together sometime after the events of book 4 but before book 5 started. What started out as Floyd seeking Yuu out because she was entertaining, became him seeking her out as he started craving her attention and being around her made it feel as if he could be himself without being judged. Yuu saw Floyd as someone to tag along with if you were bored and it swiftly became that she wanted to see him smile more, hear him laugh, hear him do anything. Both of them fuel the chaos the other can bring, but Yuu can calmly talk Floyd down unless someone pissed her off, then you got both angry at someone.
They very much love each other and it's nigh constant honeymoon phase for the pair.
Best Friend:
Ace and Yuu is self explanatory, one of the first jokers that managed to worm his way into her heart, even if she wants to kick his ass 50% of the time. While Yuu tries not to get into the shenanigans Ace finds himself in, sometimes caused by his own fault, she can't help but be pulled along for the ride. And as the story goes in TWST, She and our Adeuce combo are a set, do not separate.
Deuce and Yuu is also self explanatory, a pair of delinquents becoming best friends. Yuu was more than set for hating this world but seeing how Deuce tried to genuinely help her at every turn, made her change her mind. Deuce is the sole reason Yuu managed to open up to the students at NRC. Even though he didn't know she was a girl at first, it didn't change how he treated her once it was revealed (although he was a little shy when speaking to her afterwards).
Leona and Yuu grew to be friends after the stunt she pulled when she and Grim had to crash at Savanaclaw. Yuu had a habit of being able to find him and, for once, Leona didn't mind someone's company. The two end up talking, sleeping, or sometimes they can be seen playing chess or shogi (Yuu introduced it to him after talking about it). Leona grew to fall in love with Yuu and Yuu herself developed a crush on him. Of course, when she got with Floyd, that tanked their relationship for a bit and it only fixed itself after she sat him down and talked about it. The crush rears its head every now and then, but they're still best friends and that's something Leona absolutely treasures.
Jack and Yuu became very fast friends during the events of book 2 and it just grew from there. Out of all the first years, Jack is the one Yuu respects the most and if he ever gets in trouble. she would bail him out in a second (Ace and Deuce cause too much trouble so she waits to come to their aid). Jack is stronger that Yuu and they often have arm wrestling matches to she how far she's come. He's also her gym buddy, along with Epel, and Jack often pushes Yuu to do better.
Epel and Yuu are a pair of chaotic people when together, often times giving Vil a headache in the process. Yuu didn't like the gendering nonsense Epel did during book 5, but eventually they became good friends. Epel often breaks out into his country accent around Yuu and she can only understand about half of it, but still lets him speak. Once Epel saw that Yuu has muscles, he started tagging along with her and Jack so that he could try and get strong like them.
Ortho and Yuu's relationship is that image from B99 with Rosa holding the dog. "I've known Ortho for a day but if anything were to happen to him, I would kill everyone in this room and then myself." Yuu adores Ortho and really can't say no to him and he uses that to his advantage for getting her to come hang out with him and Idia. Even after the events of book 6, she couldn't find it in herself to be mad at him. Ortho sees Yuu as a big sister and always loves having her around.
Friend:
Cater and Yuu didn't get along at first, due to Yuu not really liking Cater's personality. They became slow friends and now Cater goes to Yuu if he needs to unwind and put his fake smile to rest. Yuu makes Cater spicy desserts and he became addicted really fast to them.
Jade and Yuu's friendship didn't really start until after her and Floyd got together. Yuu decided that she wanted to know more about Jade since they both share a love of nature. Jade was caught off-guard by her openness to wanting to know him, which he at first chalked up to her doing so out of obligation for dating Floyd. Jade has become quite protective of Yuu as well, both because she's Floyds partner and because she's a friend.
Kalim and Yuu's friendship is an interesting one. Basically, as soon as they meet, it started, which was unknown to Yuu at the time. Kalim's happy personality could give Yuu cavities and she can only handle so much of it at a time. He comes to her for help on how to do things himself, such as cooking and cleaning, She has received so many gifts from him for her help, that she can't say no to due to Kalim refusing to listen.
Vil and Yuu are a very interesting friendship. Yuu thought he was gonna be one of those "mean girls" at first, but soon learned that he wasn't. Yuu often tells Vil that he doesn't have to keep up that model persona around her and to just been a teenager. Vil has learned a bit from Yuu, namely how she handles herself around a school full of guys. Yuu and Vil constantly be beating those "You should act like your gender" nonsense. Both also bond over their shared dislike of Neige.
Idia and Yuu are video game buddies. He was shy around her at first, until he learned of her gaming knowledge, now they both complain about their SR and UR luck. Idia invites Yuu over for gaming tournaments and she is a menace in any team match.
Malleus and Yuu's friendship is different than how it's portrayed in the game. Although Malleus seeks Yuu out at night for talks, she sometimes keeps her distance from him. She finds him off-putting in a sense, but does like Malleus enough to form a friendship and give him the nickname of "Tsunotaro".
Lilia and Yuu's relationship is just literally them both hyping each other up. Lilia, when he comes to Yuu asking if he looks cute in an outfit and Yuu, when she comes to Lilia for somewhat stupid things. She has also banned him from her kitchen in Ramshackle after he bent one of the pots.
Sebek and Yuu's friendship definitely one that needs time to improve and grow. But they are friends, learning how the other one works. Given that Yuu is Mallues' friend, Sebek wanted to make sure she wasn't planning anything foul that morphed into him protecting her without him realizing it. Yuu tends to keep Sebek on his toes when she does stupid stunts.
Acquaintance to Friend:
Riddle and Yuu's is a slow process, but Riddle appreciates it. Yuu's basically having to rewrite what was established in his head by his harpy of a mother. Riddle does question Yuu's chose of a partner, but on the other hand, she has saved Riddle from being annoyed by Floyd.
Trey and Yuu are baking buddies. Often time spilling out their problems as they bake. Yuu has apologized to Trey for what she said about him during book 1, Trey said that she was right and she didn't have to. Trey has unintentionally become a big brother to her, despite them being the same age.
Ruggie and Yuu are the "Broke Buddies". Ruggies sometimes stops by Ramshackle when he needs a break, or when Yuu has made donuts. The two aren't seen together often, but if they are, that means they've most likely stolen something from someone. Ruggie sometimes uses "Laugh with me" on people who annoyed Yuu.
Jamil and Yuu's friendship was probably the longest it took to fix. Starting out from acquaintance, to being dislike, then back to acquaintance, and slowly becoming a friend. She straight up kept calling him "Viper" until the end of book 5. Jamil no longer sees Yuu as a nuisance, but the two sometimes mess with each other and often Jamil goes to Ramshackle to relax (and escape Kalim)
Acquaintance:
Azul and Yuu's friendship is more of Azul being only slightly scared of Yuu after book 3 (She beat him up with a part of the lounge that broke off during his overblot). He sometimes calls on Yuu to try and wrangle Floyd, but doesn't realize his mistake until it's too late. Weirdly enough, Yuu is sorta protective of Azul and somehow ended up becoming an enforcer like Jade and Floyd.
Rook and Yuu is Yuu trying her hardest with Rook and his personality, but Rook is rook. She doesn't hate him, she's just a little unnerved by him, but she can count of Rook to have her back in situations. Rook, of course, sings Yuu's praises for everything she does. The ultimate unhinged hype man.
Silver and Yuu's friendship is tied into the rest of the Diasomnia family, but she is curious about him. He's a mystery to her. Silver on the other hand, likes Yuu. He likes how much she means to the other Diasomnia members, likes how much time she spends with Lilia. He would also protect her in a heartbeat.
