- Caste: Samurai
- Clan: Hikiji (previously Mifune)
- Profession: Shugyosha (Student Warrior)
- Sensei: Katsuichi
- Anthropomorphic Identity: Rabbit
Introduced very early in the Usagi saga, Jotaro has taken on an ever increasingly important role in the story. He was born in the same village as Usagi, to Mariko. Usagi first met Jotaro after the boy had been captured by the Mogura Ninja, and ends up rescuing him. Later Jotaro leaves his village to walk the warrior's path with Usagi, and the two have many adventures. Currently Jotaro is training with Usagi's former Sensei, Katsuichi. He is almost of an age to receive his top knot and become a full samurai.
He is Usagi's son. As is eventually told throughout the saga, Usagi and Mariko had a brief affair just before Usagi left to serve Lord Minune. This resulted in Mariko getting pregnant. Kenichi married her shortly after knowing she was pregnant with another's child. Usagi was not informed. Their son, Jotaro, was raised by Mariko and Kenichi and also was not told the truth about his parentage. The secret, and the relationship between these four characters, develops over the course of the Usagi saga. Currently both Jotaro and Usagi know the truth, but is not aware of the other's knowledge.