|Japanese name:||寺井 黄之助|
|First appearance:||Magic Kaito Chapter 1|
Conan Anime: Episode 219
|Japanese voice:||Kaneta Kimotsuki (219)|
Koji Yada (Magic Kaito)
Jii worked as the famous magician Toichi Kuroba's assistant. He also knew of Toichi's alter ego as the Kaitou Kid, and presumably assisted him in his heists. According to Jii, Toichi made him swear never to tell his son Kaito about his father's secret identity. Because Kaito did not immediately recognize Jii, it seems that he may not have been close to the entire Kuroba family, or perhaps Toichi wanted to protect Kaito from his Kaitou Kid identity, and thus kept him away from Jii.
Since Toichi's death, it seems that Jii has opened a pool room. 
Jii first appears in the opening file of Magic Kaito, where he dresses as the Kaitou Kid and steals a diamond using a magic trick that makes most of his body disappear. After Kaito stumbles through the trap door to his father's Kaitou Kid room and realizes that his father was the original Kid who disappeared eight years ago, he decides to dress as the Kid and discover the identity of the current Kaitou Kid.
Kaito confronts Jii on the top of a building and manages to see through Jii's disappearing trick. Jii mistakes Kaito for his father, then Kaito recognizes Jii from tapes of his father's magic shows. Jii tells Kaito that Toichi was murdered eight years ago, and that he, Jii, had donned the costume in an attempt to lure out the murderers. Kaito immediately decides to become the Kid, to Jii's seeming dismay, but Jii's advanced age make it clear that Kaito has a better chance of successfully pulling off heists than Jii does.
Since then, Jii has appeared to offer Kaito advice and sometimes assist him in his heists. It was implied that the Kid's 'assistant' in the Magical Midair Walk and in the Teleportation Heist was Jii himself.
- In the "Teleportation Magic" case Conan catches a glimpse of the Kid's assistant. In the manga, this is fairly clearly Jii himself, judging from his hairstyle and body shape. In the anime depiction, however, Kid's assistant is depicted as a figure identical to Kaito himself, albeit with a shadowed face.
- ^ Magic Kaito Vol. 2, Ch. 7 (Hustler vs Magician)
- ^ Magic Kaito Manga Volume 1: Chapter 1, Magic Kaito Special Episode 1 (The ResurrectedKaitou)
- ^ Detective Conan Volume 44: Chapters 7-10. Episode 356 (Kaitou Kid's Magical Midair Walk)
- ^ Detective Conan Volume 61: Chapters 1-4, Episode 515 (Kaitou Kid's Teleportation Magic)