A God Eater veteran at the age of only 18. Being so taciturn, he hates interacting with others. He is believed to have a much larger strength capacity than the other team members.

Souma is a member of the 1st unit of the Far East Branch of Fenrir, led by his best friend and long-time comrade Lindow Amamiya. He has a bad reputation of losing comrades whenever they are on a mission with him, which leads many to believe he's cursed.