Shigeki Birkin is a character in the killer7 universe and the protagonist of the Killer is Dead story. He is an assassin who lives in an apartment in Seattle, Washington and kills using a baseball bat, giving him his title, "The Batman". In Killer is Dead, Birkin receives a threatening letter from Curtis Blackburn and has to ally with Christopher Mills and Dan Smith to protect himself from the man. Birkin is highly psychotic, being shown to kill people even when they are not his target.