- An Old Blood vampire that sided with the humans to fight against the Kowloon children during the Kowloon Shock. Jiro was transformed into a vampire in 19th Century London. He used to be a lieutenant in the Imperial Japanese Navy until he was severely injured in a fight protecting Alice and Jasmine. Besides being an Old Blood, he also comes from a very special bloodline: the blood of the Sage. He wields a long katana which has a blade made of silver. During the war, after defeating most of the Kowloon children, he became known as the Silver Blade and the Kin-killer. He is able to use some of the Kowloon powers as well as those of his own unique bloodline to be able to challenge even the Kowloon King and the three powers of the Special Zone.
- He is weak against sunlight and water. He is shown being burned to the bones from staying into the ocean too long and releasing smoke under the sunlight, even though he was carrying an umbrella. He has a little brother, Kotaro, who is the only other vampire who shares his bloodline. He is considered to be the chosen Guardian. As the chosen guardian, he is devoted to returning the sage's blood, which resides within him, into her reborn body, Kotaro. He reveals to Mimiko that once Kotaro fully matures and he gives back the sage's blood, he will no longer be around.
- Jiro possesses a very calm and matured attitude he cares for his brother, Kotaro, deeply , he also possesses great sword skill, however, despite this he has cocky tendancies, such as when he goes up againt Cassa. He has also shown to care very much for Mimiko.
- Jiro appears as a very good looking young man, with long black hair falling down his back He has dark grey eyes in which appears in some scenes in the dark appear to glow blue with long pupils his attire seems steam punk which uses the colors of red black and blue he wears red slacks a black button up shirt and a red overcoat he also ties a wide blue ribbon around his neck he also sports goggles hanging loosely around his neck in which he uses when he goes outside during the day himself being a vampire also sports fangs.
His appearance is closely similar to a character named Alucard (who is also a vampire) from another anime: "Hellsing", the resembles are clothes such as the hat (difference in that be the metal around Jiros' and Jiro hat is slightly smaller) hat is also shared with Dr.Jerkll on the anime get backers just black) also style of dress although Jiros' is slightly more modern also there hair but that is where the resembles end.