An old blood vampire and Hero of the Kowloon shock in Hong Kong. Jiro was transformed into a vampire in 19th century London by the Founder of the Sage bloodline Alice Eve. He was a lieutenant in the Imperial Japanese Navy when he met and fell in love with Alice, and was severely injured in a fight protecting her. Because of her love for him, Alice turned Jiro into a vampire, without giving him the choice as is the usual custom.

Besides being an old blood, he comes from a very special bloodline: the Blood of the Sage. the only vampire Alice (the founder and only member of the bloodline) ever made. As Jiro is of the only vampire made of the Sage bloodline he is the "guardian" charged with the duty of returning the blood to the reincarnation of Alice Eve, (Kotaro Mochizuki) so that she may regain her memories and power. He tells Mimiko that this is his sacred duty, one that he is honored to carry out. He states that when it is time, Kotaro will drink him dry and that he will no longer be, whether or not this means he will die is unknown.

He wields a long katana which has a blade made of pure silver - from which his name of 'silver blade' comes from, a name he aquired during the war after defeating most of the Kowloon children. His weaknesses include sunlight and water; as he is shown burned to the bone from staying in the ocean too long, and releasing smoke under the sunlight, even though he walks under an umberella.

Jiro is polite, calm and a gentleman although he does tease Mimiko from time to time. He is very protective of his little brother Kotaro (the reincarnation of Alice Eve) and becomes worried when seperated from him, although that doesn't stop him from punishing Kotaro when he has done wrong.