Hattori Zenzou is a highly skilled ninja who sports a light-brown/dark-blonde mop top and a goatee. Initially introduced as a cloaked ninja assisting in the fraudulent "Dreamcatcher" scheme, his first notable appearance was when he and Gintoki attempt to fight to the death over the last remaining issue of a Christmas Double Issue Akamaru Jump.
He is the first ninja in the series to apparently equal Gintoki's obsessive devotion to Jump. He apparently suffers from piles. He commands a freelance ninja team known as the "Shinobi 5." His father is said to be the strongest man in the Oniwabanshū, and an instructor to many of his peers, including Sarutoubi Ayame.