Ring | JoJo's Bizarre Adventure | Jotaro's Hat

JoJo's Bizarre Adventure (ジョジョの奇妙な冒険, JoJo no Kimyō na Bōken), often shortened to JoJo or abbreviated as JJBA, is a shonen and seinen manga written and illustrated by Hirohiko Araki. JoJo's genre spans Action, Adventure, Supernatural, Thriller, Comedy, Tragedy, Mystery, Slice of Life, and Horror. (from JoJo's Bizarre Encyclopedia)

The nickname "JoJo" is an abbreviation of the name of the Joestar family protagonists (Jonathan, Joseph, Jotaro, Josuke, Jolyne, Johnny, Jodio) in each of the eight manga story arcs whose adventures it chronicles.