Kusuo helped lead a rebellion against Metori after he got Kusuo's dad transferred to Siberia.
Metori developed a crush on Kokomi which made him want to transfer to PK just to be near her.
Kaidou gets easily tempted by Saiko's wealth and items.
Metori was moved when Riki threw away money to save a kid and seems to somewhat respect him. Riki thinks that he is still in Metori's debt and considers himself his henchman. Riki also considers them to be friends, although Metori outwardly denies the idea of it.
Aren has no problem sticking up for himself and as such Metori's and Aren's prides often collide, resulting in frequent verbal fights and beatdowns with each other. Even so Metori has gone to great lengths to impress him and Aren has shown to care about Metori and his well-being in return.