An exchange student to Heartland Middle School and a huge fan of Yuma Tsukumo. Rei has his own catchphrase: "think positive." He quickly becomes Yuma's friend, and has a borderline fan-boyish personality towards him. Ray has a very cheerful and loud exterior, which exasperates others at times. He is also very friendly and eager-to-please, but tends to rush recklessly into things and is quite clumsy. Although he usually has good intentions, Rei tends to cause problems or make things worse.
It was revealed later that he was Vector, the cruelest Barian Emperor. (Rei is Vector's human form). Cruel and sadistic, he enjoys tormenting others for his amusement, even shown to have no compassion for his fellow Barians, even insulting them when they are hurt