Yūgo/Relationship

Yūto
Yūgo has an antagonistic relationship with Yūto and he travels from one dimension to another to find him so he can defeat him. Their animosity towards each other was strong enough to make them act first before thinking further. This turns out to be a misunderstanding between the two of them. Yūgo mistook Yūto as Yūri, who kidnapped Rin, while Yūto mistook Yūgo as one of Academia Duelists when the latter challenged him instead of answering his question on their first meeting.

Rin
Rin is Yūgo's childhood friend. They both are orphans who grew up together. Both shares the same dream to Duel Jack Atlas one day, building Yūgo's Duel Runner together. Rin acts like a mother for Yūgo, always scolding him for his recklessness and short temper that often gets him into trouble, which sometimes annoys Yūgo. It was shown that Yūgo harbours feelings for Rin, blushing and grinning happily when Yuzu thought that Rin was his girlfriend. While it was still unknown whether Rin return his feeling or not, both are clearly close to one another. Yūgo's feelings for Rin is what driving him to find Yūri and save Rin.

Yuzu Hīragi
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.

Yūri
After learning about Yūri, Yūgo transferred his hatred of Yūto to Yūri. His reason, like Yūto's, is because Yūri kidnapped someone close to him, in this case, Rin. Yūri is also one of the reasons why Yūgo went after Yūto due to them looking alike.