Yuto and Yuya first met when Yuto was dueling Sora. Yuya joined the duel against Yuto. Soon after the duel Yugo came and dueled Yuto. Yuto lost the duel with Yugo, saved Yuya from an attack from Yugo, and was absorbed by Yuya. Sharing the same beliefs of dueling should be used for making people smile and bring happiness Yuto trusted him with his card: Dark Rebellion Xyz Dragon. After Yuto merged with Yuya it caused Yuya to go into a Awakened state where he no longer cares for making people happy and enjoys hurting others in duels. Yuya was scared of Yuto's anger but eventually Yuya understood Yuto's pain for losing his home and friends after seeing his memories. Shortly after arriving at Heartland City in the Xyz Dimension, Yuto began actively interacting with Yuya within his subconscious and both quickly came to fully trust each other and work together to fight Duel Academy.
In the manga adaptation of Yu-Gi-Oh! Arc-V, instead of the two being dimensional counterparts of one another, Yuto is featured as one of Yuya's three older brothers, beside Yugo and Yuri, who cares deeply about his youngest brother. When they were little kids they had playful duels with one another, while creating complex Duel situations and resolve them, Yugo and Yuri. As they grew together in their father's care, Yusho creating the World Illusion so they'll have a safe place to retreat to on the end of their world, along with having the chance to find the Genesis Omega Dragon card in the past. That fateful day finally came on Yuya's birthday. Yuto had made Yuya a boxed lunch as his birthday gift to him, as he, Yuri and Yugo compete which one of their gifts that Yuya would love the most. Because Yuya is watching Yugo's championship Turbo duel he knew that giving his brother a cake in public would probably embarrass Yuya, and figured that a boxed lunch with all of Yuya's favorite lunch food would be the best choice. To make sure that he gives Yuya his gift first, Yuto and Yuri make their way to the Turbo duel. Where a call from their father explains the chaos that is happening around them, before Yuto, Yuya and their brothers make their way to the pods that will bring them to the World Illusion. On the way to them Yuya pushes Yuto and their two other brothers out of the away of the falling rumble and gets knocked unconscious, and even though they were able to reach the pods only one remained standing while the other three were destroyed. Knowing that only one of them can be saved, Yuto didn't hesitate as he and the others picked Yuya's safety over theirs. As the world came to the end, the thought of Yuya and it being his birthday brought Yuto joy in his final living moments.
For some reason Yuto's spirit, along with Yuri and Yugos', ended up being placed inside Yuya, who's memory of Yuto and their brothers were forgotten. In which causes Yuya to believe that Yuto is one of his alternate personalities. Wanting to spare Yuya of any pain about their passing, Yuto and others decided to allow Yuya to think so while making sure that his lost memories of them don't return. As Yuya began his quest to find the G.O.D. card in the first six months, Yuto learns that Yuya can allow him to take control of his body whenever Yuya needs his Xyz summoning skills, or his face for Yuya to find behind.
This is one of the less popular ships in the fandom due to Yuzu's feelings towards Yuya and Ruri's feelings towards Yuto. While Yuya and Yuto are mostly thought of having a brotherly relationship by fans, which is why a few fanfics feature the two as brothers beside Yugo and Yuri (like the four of them are in the manga version of anime), or are seen as having a bromance, some fans make jokes about "Yuto being inside of Yuya".
Despite the lack of screen time of Yuto being alive with Yuya their chemistry hits off fast from Yuto saving Yuya from Yugo's attack and giving him his card. Because Yuto's talks to Yuya from time to time from within him and the manga having Yuya "transform" into Yuto whenever he needs Yuto's XYZ Summons, it has inspired a few fans who compare them with Yugi Muto and Atem, since Yugi shares his body with Atem while the spirit lends the young duelist his skills. Along with the fact that Yuto's hair style is very similar to Yugi and Atems'.
- Yuya's Relationship with Yuto (Anime) on the Yu-Gi-Oh! Wiki
- Yuto's Relationship with Yuya (Anime) on the Yu-Gi-Oh! Wiki
- Yuya's Relationship with Yuto (Manga) on the Yu-Gi-Oh! Wiki
- Yuto's Relationship with Yuya (Manga) on the Yu-Gi-Oh! Wiki
- This ship is so named because Yuto is one of Yuya's dimensional counterparts.