Riki RyugasakiRiki stated that Ryuken has a brotherly figure to everyone. Ryuken takes the responsibility of training them.
Ryuken and Basara get along well than the others. Ryuken suggested he help Basara to complete the Dragon Trial.
Hiro & Shurato
Ryuken and Ryukai are good friends with Hiro and Shurato since a few years ago.