Zanpakuto: Shinso
Gin's got a pretty standard look overall—just a captain's cloak with an unusual lime green lining on the inside. What really stands out is everything else: his perpetually slitted eyes, his thin frame, and that distinctive silvery hair with a purple tint in the anime. He's almost always wearing a wide smile, and people have rarely seen him drop it.
The unsettling part isn't his appearance, though. It's his complete lack of visible emotion when he speaks, combined with his constant sarcasm. That combination creeps people out. Toshiro and Rukia are especially wary of him—Rukia once said talking to him felt like snakes were coiling around her neck. Even Kaname Tousen acknowledged that Gin has that effect on basically everyone, which he cited when explaining why Wonderwice Margera was so terrified of him. In the anime, he speaks in a Kyoto dialect that's indirect and polite, though his English dub carries that same politeness with a heavy layer of mockery underneath.
Ichigo's taken to calling him "Kitsune"—literally Fox-Faced.
Gin's past is pretty murky, but what's known is that he saved Rangiku Matsumoto's life once, and they've been close ever since. She's genuinely one of the few people he seems to actually care about.
He's basically a prodigy: he graduated from the Shinigami academy in just one year at a young age—the fastest graduation on record. He earned a seated position immediately based on pure talent. Around the same time, Kisuke Urahara was becoming a captain. Gin served as lieutenant under Sosuke Aizen in the 5th Division before taking over the 3rd Division as captain, which happened around the same time Byakuya Kuchiki became captain as well.
Content compiled by AnimeList.moe from publicly available sources.