Gin is a fictional character in the anime and manga series Case Closed.
Gin is a dangerous and highly ranked member in the "Black Organization". He is the one that force-fed Jimmy Kudo (Shin'ichi Kudo in the Japanese version) with APTX4869, the drug that turned Jimmy into Conan Edogawa. Wearing all black and long yellow/blonde hair, Gin is a tall person, who always covers his eyes with his black hat. He is always looking for Shiho Miyano (also known as Ai Haibara), assassinating some member of the organization or some soul and blackmailing someone.
He is usually seen being followed around by his lower ranked comrade, Vodka, who doesn't really add much to the missions other than being there. Vodka's low rank status is noted in how he calls Gin "Aniki" (or brother), which is what a low-ranked gang member calls a high-ranked gang member.
Since Gin is normally leading the Black Organization's operations he probably has a high position in the Black Organization.