Ruri Kurosaki/Relationship

Shun Kurosaki & Yūto
Ruri has a very close relationship with Shun and Yūto, her older brother and close friend, respectively. From the flashbacks and the way she was mentioned by those close to her, Ruri was hardly separated from Shun and Yūto, the three of them often sticking close together. After she was kidnapped, both Shun and Yūto have been frantically searched for her and strongly determined to save her since then.

Her older brother, in particular, was so obsessed in saving her that he was going as far as carding innocent people to lure out the son of the man responsible for her kidnap and even threatened Yūto, his own best friend, that he will destroy him to if he's getting in his way. Ruri has been the main driving force that pushes Shun to continue fighting against Academia.

Yūto has also shown a strong protective towards her, protecting Yuzu when he mistook her as Ruri as he said that he doesn't want Ruri to get hurt anymore. Saving Ruri becomes one of Yūto's main motivations to defeat Academia, and he continues to think of her dearly. Ruri has developed feelings for Yūto ever since they first met, which Yūto mutually returned. The two grow so close that they exchanged knowledge of their respective decks and even had an intimate moment together, in which both were blushing shyly but nonetheless happy with each other's presence.

Sayaka Sasayama
Despite studying in different branches and their branches have strong rivalry towards one another, Ruri becomes close friend with Sayaka. The two girls has been shown to have friendly Duels and hung out together several times. When Ruri was kidnapped right in front of her eyes, Sayaka feels guilty and has been blaming herself for her inability to muster up her courage to help Ruri, crying when she remembered her times with her. Sayaka even originally wanted to give Ruri "Little Fairy", her most important card because to her, Ruri is her most important friend, showing how close they are.