Yūri/Relationship

Leo Akaba
Even though Yūri doesn't care of Academia's goal and only joins to have some fun, and the professor knows about his origin, he appears to be very loyal to Leo, obeying all of his commands. He will do his best to fulfil his given order and didn't dare to disobey it. As such, despite wanting to turn Yuzu into card, he didn't do so because Leo had ordered him to bring her back unscathed. Yūri seems to be one of Leo's most trusted Duelists amongst Academia, as he personally gave only Yūri alone the order to capture Yuzu and her dimensional counterparts, something that only a few Academia Duelists knows. And Leo only ordered Yūri to fulfil the mission, proving that Leo is confident in Yūri's skill.

Dennis Macfield
Dennis is Yūri's acquaintance. Their relationship hasn't been explored further, but both seems to have known each other for long times since Dennis has helped Yūri in locating both Ruri, Yuzu, and Serena. Dennis knows Yūri enough to be confident of Yūri's skill, trusting Yūri to handle his mission alone.

Yūgo
Yūri first met Yūgo when he kidnapped Rin, Yūgo's childhood friend. Since then, Yūgo bears a strong hatred towards Yūri and travels from one dimension to another to hunt him down. Yūgo's obsession on Dueling him quite annoyed Yūri, who only saw Yūgo as bothersome and doesn't worth his time, usually ignoring Yūgo when the latter challenged him to Duel and instead continuing his mission. Yūri's interest in Yūgo started to spark when he found out that Yūgo had defeated Serena, and finally agreed to his challenge as he now considers Yūgo capable of providing more fun to his hunting game. After his last duel against Yūgo, Yūri told Yūgo that he is the most worthy opponent in his life and apologizes to him for treating him like a nuisance, as he absorbs Yūgo.

Yūya Sakaki
When first hearing about their similar appearances from Dennis, Yūri showed a little interest in Yūya. After absorbing Yūgo, Yūri gained the new powers and one of them was sensing Yūya's presence. The massive amount of power he gained gave him the interest to become one with Yūya. During his duel with Yūshō Sakaki, Yūri later showed to have gained a possessive desire to merge with Yūya, shouting at Yūshō that Yūya was his and he wouldn't let anyone else have him. Yūya refused Yūri's wishes and gained an intense hatred for Yūri after he carded his father and finally accepted his challenge just for revenge.