Ken (ケン) is a non-player character who runs the Headquarters. Ken is the brother of Hokage Yudai and Aiko, grandson of Chiyo, uncle of Norobi, stepbrother of Anaki, and a cousin of Vadar.
During the Chunin Campaign, Ken is revealed to have an evil stepbrother named Anaki, who helps the S-Ranked criminal Kojima to kidnap him, but Ken gets rescued by the main character, Shin, and Genzu.
- Level 6 - Ken's Challenge (first appearance)
- Level 13 - Ken's Second Challenge
- Level 18 - Ken's Third Challenge
- Level 22 - Hidden Laboratory
- Unnamed Kinjutsu: Ken used a Kinjutsu during his challenges to create Undead Marionettes.