Sakata Gintoki is a samurai living in an era when samurai are no longer needed. To add to his troubles, oppressive aliens have moved in to invade. Gintoki lives with Kagura and Shinpachi, taking on odd jobs to make the world a better place...and to pay their rent. In the Joi war, he was known as the "White Devil" (Shiroyasha) due to his silver hair and white coat he wore in battle, which, combined with his impressive capabilities as a swordsman, made him famous among his comrades and struck fear into Amanto.
Gintoki has naturally permed silver hair, which he blames for his lacking love-life. He has a big crush on the TV's news weather girl, Ketsuno. In fact, to date, the only time he is seen to have blushed is when he tries to make use of Sadaharu and Ketsuno's dog to get a chance to talk to her. Though several female characters have shown an interest in Gintoki, he usually does not show any response back and merely puts up with them as annoyances.
Gin has two major obsessions in life. He is obsessed with sweet foods such as parfait, ice cream and cake. His second obsession is reading the manga anthology magazine Weekly Shōnen Jump. (Which, not coincidentally, is where Gintama is published in). Gin will go to great lengths to get the latest Jump issue, to the point of reckless behavior. His Jump obsession makes him easily dream of being like other Jump heroes, including wishing that he had a "Bankai" similar to the hero characters of Bleach.
Despite his appearance and initial behavior, Gintoki has a great amount of pride for the old bushido code. He takes it upon himself to rescue or avenge not only his comrades and friends but also people he barely got acquainted to, be it a pit-fighter who was taking care of abandoned orphans or an Amanto who resembles a kappa.
Despite being a fearsome fighter with nearly unmatched skills, he avoids needless bloodshed after suffering the loss of most of his friends and allies during the Joi war.