Annasui was a child who had an intense fascination with disassembling objects. He spent much of his childhood taking apart various items that caught his interest, which made him somewhat of an outsider among his peers. One day, while returning from work, he discovered that his girlfriend was cheating on him with another man. In a fit of rage, Annasui tore both of them apart. He was subsequently arrested and sentenced to twelve years in prison for first degree murder. Despite briefly crossing paths with Weather Report by Hermes, Annasui did not become involved with Jolyne until F.F. sought his assistance in Emporio. Driven by a deep love for her, Annasui agreed to serve as Jolyne's bodyguard. Throughout their relationship, he remained loyal and protective of her, even at the cost of sacrificing himself at times.