A hysterically comical private investigator who befriends and helps Kikaider and his companions. He is a descendant of the famous real-life ninja Hanzō Hattori. Hanpei is derisively nicknamed "Hanpen" by his companions (hanpen is Japanese for "pounded fish cake"). Even the usually very polite Jiro will sometimes use the name Hanpen. Hanpei "Hanpen" Hattori is played by Shun Ueda.