Yuzu Hīragi/Relationship

Shūzō Hīragi
Having lost her mother not long after she was born, Shūzō is the only family she has and cherish him deeply. Similarly for Shūzō, Yuzu is the only daughter he has and has taken care of her ever since she was a baby alone, making him grew to have deep fondness for his daughter. This caused him to get depressed whenever Yuzu wasn't around and angry if there is a boy that he thinks getting too close to his daughter. Yuzu is shown to get occasionally annoyed by her father due to his goofy nature, often smacking him with her paper fan whenever he does something foolish. But as a father and daughter, they care for each other, and Shūzō would support and cheer for Yuzu as she Duels, and Yuzu in return promises that she will win.

Yūya Sakaki
Yuzu is Yūya's childhood friend and became an older sister figure for him. Among Yūya's friends, she is the one who is seen hanging around with Yūya the most, but Yuzu would at times get annoyed when Yūya makes her angry which causes her to hit him with a paper fan. Both are very close with each other, always supporting one another when either of them are depressed of something. Yuzu's feelings for Yūya is actually more than just a friend; when Sora mistook her as Yūya's girlfriend, she blushes, and is also jealous whenever Mieru makes an advance or calls him "Darling". Unfortunately, Yūya is oblivious to her feeling, even protesting at the prospect of dating a crude strong girl like Yuzu when Sora mistook them as a couple. Though, there were times Yūya's feelings for Yuzu seems to be more than just a friend in lots of ways during the series. Regardless, Yuzu is someone that Yūya cherish deeply, even more than his other friends. This is shown during the aftermath of Battle Royal that showed Yuzu being the person that Yūya worried the most and his main motivation to join Lancers is to save Yuzu. As Yūya became more vulnerable on entering the Awakening state, Yuzu started to fear and grow worried of his emotional state, so much that she eventually told Yūya in his Duel against Sergey that she doesn't recognise him when he behaved that way and doesn't want to see him like that again. Her feelings for Yūya remains the same even after knowing his origin as the reincarnation of Demon Duelist, still placing her utmost trust in him.

Sora Shiun'in
Sora became Yuzu's teacher after she begged him to teach her Fusion Summon. Ever since then, both spent so much times with each other training Fusion Summon. Thus, Sora and Yuzu formed a strong teacher-apprentice relationship. Sora initially thought that Academia's goal was more important than his friendship with Yūya and Yuzu. But Sora's loyalty to Academia began to falter when he thought Yuzu was captured by Obelisk Force for being mistaken as Serena and quickly returned to Academia to find her, and after knowing that Leo is targeting Yuzu. When reunited with Yūya and Yuzu in Synchro Dimension, Sora revealed his true feelings that he genuinely thinks of Yūya and Yuzu as his friends and tried to convince both of them no to involve themselves with the Dimensional War, but seeing their resolve to stop the war caused Sora to be torn between Academia's goal and his friends' safety, as while he still believes that Academia's goal is righteous, he doesn't want fulfil it if it means harming Yūya and Yuzu. Sora eventually realized how precious Yūya and Yuzu are to him and couldn't bring himself to carry out his order if it means sacrificing them, leading him to finally betray Academia for the sake of protecting his friends. In return, Yuzu trusts Sora as her friend and knows that he is different from other Academia Duelists while the others didn't.

Futoshi, Tatsuya, and Ayu
Yuzu acts as an older sister figure to them, guiding and supporting them in their Duels. Futoshi, Tatsuya, and Ayu fondly calls her "Yuzu-neechan" and usually waiting for her and Yūya in front of their school gate after school to go home or going to Duel School together. Aside from their Duel School activities, the three children sometimes also help Yuzu shopping at grocery stores.

Masumi Kōtsu
Yuzu developed rivalry against Masumi after she got defeated by her in their Duel with You Show Duel School on the line. Upset at being beaten by Masumi, Yuzu decided to learn Fusion Summon so she can fight against Masumi on even ground, vowing to defeat her. Masumi initially didn't pay any attention to Yuzu and looked down on her as a Duelist. Only after Yuzu defeated her in Maiami Championship she finally acknowledges her as a rival, giving her "Crystal Rose".

Yūto
When she first met Yūto, he mistook her for Ruri and thus grow protective of her while she mistook him for Yūya. After she encounterd him, Yuzu started to doubt who Yūto was and thought he was Yūya in a costume. Even after knowing that Yuzu is not Ruri, he still continues to look after her, not wanting her to get hurt nor involved in his battle and wishes for her to survive if it cannot be avoided. While initially wary of Yūto, she eventually realized that he is not a bad person, and like Yūya, he wishes to protect his friends and bring happiness to people. Thus, Yuzu come to his defence when Serena implied that Yūto and Shun were lying about their dimension's tragedy and cleared up the misunderstanding between him and Yūgo.

Yūgo
Yuzu was saved from Yūri by Yūgo, who mistook her for Rin. When they were in the Synchro Dimension, Yūgo and Yuzu built a quick friendship. Yūgo attempts to help out Yuzu with the issue of the Interdimensional Domination in any way he can, such as helping her warning other citizens. Yuzu shows concern for Yūgo, though she has been frequently annoyed by him, due to him often mistaking her for Rin and if he was being insensitive, causing her to hit him with her fan, or threatening to do so. Yūgo was saddened when he witnessed Yuzu's defeat at Sergey's hand and cried for her, believing she was dead. Since then, he promised to continue fighting and win for her sake as well. When he found out she was alive, he was so happy that he tried to hug her. This is the first time Yūgo tried to hug Yuzu without mistaking her as Rin, showing how much he values her as a friend.

Mieru Hōchun
Yuzu and Mieru are shown to have a rivarly for Yūya's affection since they both have feelings for Yūya. Yuzu gets jealous whenever Mieru makes any advance towards him or calls him her "Darling" to the point Yuzu almost smack her with her signature paper fan if not stopped by Futoshi, Ayu, and Tatsuya. In Mieru's part, she accuses Yuzu constantly seducing Yūya due to how close they are.