Introverted, selfish and a bit cruel, Shuuichi is the manga's antihero. He is very protective of his sisters Sumire and Katsumi who are, like himself, wer born with extrasensory perception powers (or ESP). He was born in a secret government laboratory that cultivated esper (telepathic) powers, and, as a result of being used in experiments, is very untrusting towards the E.C.S.(Esper Control System). As he is one of the strongest espers in existence, he is constantly being hunted by various organizations who want to research him.