Kōnosuke Jii is an elderly man who runs a billiards parlor and bar called the Blue Parrot. In his younger years, he served as the loyal friend and assistant to the world-famous magician Toichi Kuroba. Jii was one of the few people who knew that Toichi was the original Kaitou Kid, and he likely assisted him during his heists during that time. After Toichi died under mysterious circumstances that were staged as an accident, Jii kept his promise never to tell Toichi's son Kaito about his father's secret identity. However, eight years after Toichi's death, Jii himself donned the costume of Kaitou Kid and committed a theft, using a magic trick that made most of his body disappear, in an attempt to lure out the people responsible for murdering Toichi. Kaito discovered his father's secret room and the truth of his double life, then confronted Jii on a rooftop and saw through his trick. Jii mistook Kaito for his father at first, then recognized him from old magic show tapes and revealed that Toichi had been murdered. Kaito immediately decided to become the new Kaitou Kid himself, and Jii, recognizing that his own advanced age made him less capable, agreed to assist him. Since then, Jii has acted as Kaito's behind-the-scenes supporter, helping with scouting, preparation, and occasionally participating directly in heist tricks. He is deeply loyal to the Kuroba family and is willing to take on high-risk assignments without hesitation. Jii is knowledgeable about magic from his time as a magician's assistant, and he is also a swift but reckless driver. In his personal life, he enjoys billiards and classic art. His past includes a period during World War II when, as a young man, he worked as a servant for a businessman named Koyata Yamamoto and experienced a personal tragedy involving a painting later titled the Ashiya Sunflowers, which shaped his understanding of loyalty and sacrifice. Jii addresses Kaito as young master and holds great respect for the memory of Toichi. The police are aware that the current Kaitou Kid has at least one assistant, with descriptions matching either a young woman or an elderly man, the latter being Jii. Over the course of the story, Jii remains a steady anchor for Kaito, offering advice, logistical support, and occasional hands-on help, though he generally works from the shadows. His abilities include a practical knowledge of stage magic, skilled driving, and possession of various licenses including a helicopter pilot's permit. Despite his age, he proves consistently brave and resourceful.