Rio Mason Busujima/Relationships

Samatoki Aohitsugi
Despite being hostile to each other at their first meeting, Rio and Samatoki became friends over time. Rio highly appreciates Samatoki as both leader and a friend, being always ready to follow him or help him out. He respects Samatoki's skills and his strong spirit, thinking that he would make an excellent soldier. He also likes to treat Samatoki to his cooking, being unaware that he is terrified of it.

Jyuto Iruma
As well as with Samatoki, Rio is a good friend of Jyuto, highly respecting him as a teammate. Jyuto usually acts somewhat of a guidance system for Rio, telling him where and when to use his strength. However, Rio is also able to act on his own and even persuade Jyuto, prompting him to act the right way. He also likes to treat Jyuto to his cooking, being unaware that he is terrified of it (even more than Samatoki).

Dice Arisugawa
Rio found Dice collapsed from hunger, so he brought Dice to his campsite where Rio treated him to some of his cooking. Dice was very grateful to Rio, and started to frequently visiting Rio to grab a meal. Rio thinks that Dice has quite a strong spirit and believes that he would make an excellent soldier.

During the incident at the Yokohama container yard, Rio and Dice had to fight each other. Although Rio genuinly didn't want to harm Dice, he couldn't go easy on him or accept his pity, to which Dice responded similarly.

Nemu Aohitsugi
Rio confronted Nemu when she arrived to arrest Samatoki for violation of the Hypnosis Mic usage. Rio made a claim that her actions were unreasonable, considering the fact that there are plenty of similar cases but Nemu didn't listen to him, which resulted in MAD TRIGGER CREW picking a fight with Nemu and her subordinates.

Ansho Iojaku
Being a soldier, Rio highly respects his unit commander, Ansho, being always ready to follow his orders and attack any target he points at. When their unit was sent for a mission, Ansho also showed Rio the importance of food, which he carries with him to this day. When Ansho was incarcerated by the Party of Words, Rio decided to fight Chuohku, so he could get a chance to rescue him.

Kubiki
Kubiki was Rio's squadmate during his military service, as they were good friends and loyal comrades. After the disbandment of their unit, Kubiki got in touch with Rio, offering to join him in their attack against Chuohku to save Ansho. However, Rio dismissed the offer, noting that their mission was doomed to fail and even confronted Kubiki, in order to stop him.