Obsessed with disassembling objects, Annasui grew up a bit awkward during his childhood days. He painstakingly dissected a pocket watch, his neighbor's car, and whatever else that struck his fancy. One day while returning from work, he found his girl friend cheating on him with another man. In response, he methodically tore both of them apart. He was sent to prison and a faced twelve year sentence for first degree murder.

Although he was briefly seen next to Weather Report by Hermes, Annasui doesn't get involved with Jolyne until F.F. comes to Emporio for help. Seemingly entranced by the tales he has heard of her, Annasui agrees to become Jolyne's bodyguard out of his burning love for her. Upon finding her, Annasui keeps true to his word and protects Jolyne—to the point of self-sacrificing at times.