Yūgo/Relationship

Yūto
Yūgo seems to know Yūto and said that he wanted to pay him back in the Duel. Yūgo also gets angry at Yūto when he calls him "the pawn of fusion", thus prompting Yūgo to angrily tell Yūto that he had the nerve to get his name wrong and take "what's important" to him, but Yūto argued back saying that Yūgo took something important to him.

Rin
Yūgo knows someone known as Rin who looks like Yuzu. When he first saw Yuzu, he cried out "Rin" happily and ran to hug her, showing he cares greatly for Rin. Yūgo states that Rin nags him and often scolds him, a bit like a mother. Yūgo also states that Rin is his childhood friend. It is also hinted that he has feelings for Rin as he acted embarrassed when Yuzu asks him if Rin is his girlfriend.