Yūto/Relationship

Ruri Kurosaki & Shun Kurosaki
There has been no interaction between Yūto and Ruri thus far. However, Yūto displays care and protectiveness towards Ruri as he stated to Yuzu (at that time thinking she was Ruri) that he doesn't want her to get hurt. Also, despite not wanting to hurt anyone anymore, Yūto decides to continue to fight to save her, as shown when he accepted Sora's challenge when the latter told him that he can save Ruri by destroying the Academia. He is also shown to be very supportive and defensive of Ruri as he told Shun, after he also mistook Yuzu for his little sister, that Ruri would never learn the enemies' form of summoning with a smile on her face. This being said with full determination and belief in her, showing that both are very close with each other. Shun is Yūto's Resistance comrade and best friend. Although there are disagreement between their ways on finding Ruri, they have a lot of faith and trust in each other. Yūto also refers to Shun as his best friend, protesting that the two did not run away from their homeland. He is also shown to have to keep Shun under control (sometimes with physical force) and even continued to do so after being merged with Yūya, such as when Shun angrily accused him of stealing Yūto's Duel Disk and Dragon. Shun also considers Yūto as his one and only best friend, though this didn't stop him from threatening Yūto when he felt Yūto was getting in his way of saving his sister. Shun is very concerned of Yūto's well-being, which was demonstrated when he wanted to assist Yūto in fighting Yūgo, and when he angrily accused Yūya of harming and stealing Yūto's Duel Disk and Dragon since Yūya had possession of the card. Shun understood Yūto's deep hatred for the Academia, and thus when fighting Dennis, he Duelled fiercely in his stead.

Yuzu Hīragi
Upon their first meeting, Yūto mistook Yuzu for Ruri Kurosaki. He began to grow protective of her until he discovered she was not Ruri. However, despite this knowledge, Yūto still watches over her, warning her not to get involved in their battle because he doesn't want her to get hurt and also told her that if she got involved, then he wishes for her to survive. Yuzu was initially skeptical and wary of Yūto, but eventually understood that Yūto was not a bad person, defending him when Masumi thought he was the one responsible for attacking Marco, and cleared up the misunderstanding between him and Yūgo.

Yūya Sakaki
Although they've only met for a short period of time, Yūto immediately developed a trust in Yūya because they both believed the purpose of Dueling is to make people smile and have fun. Yūto truly wishes for this, which led him to sacrifice himself for Yūya from Yūgo's Dragon. He then entrusted Yūya with his "Dark Rebellion Xyz Dragon" and told him to bring Duels with smiles for everyones' future. Like Yuzu, he is shown to be protective of Yūya as shown when he merged with Yūya to help him defeat Isao who had cornered Yūya in his Duel. Yūya also grows to trust Yūto, determined to fulfil their promise, which became one of Yūya's primary motivations to continue Duelling. As a result, the two formed a strong bond similar to that of brothers and have defended each other in many ways, such as Yūto defending Yūya from Shun's accusations and Yūya silencing Reiji when he was about to tell about the Xyz invasion because he knew how much it hurt Yūto and Shun.