Miyata Souma (宮田颯真) is Arata's best friend and former partner from the dissolved duo 'Gurney flap'. He is the one who introduced Arata to RAD WEEKEND when they were in middle school. He is currently in the hospital as a result of a car accident which paralyzed some of his body parts, causing him to be unable to sing. He is first mentioned in the STRAY BAD DOG event, though he doesn't make an appearance until THE POWER OF UNITY event. He is currently 19 years old. His hobbies include listening to folk songs and foreign music, and his favorite food is tamagoyaki.

As of Walk on and on, Souma is teaching Toya how to compose street music. Souma wants to finish an incomplete song he started before his accident, but doubts his ability to due to the partial paralysis of his body. So, Toya encourages him and offers to assist him. Souma asks Toya to keep this collaboration a secret until he has finished the song he wishes to present to Arata.