Sanosuke used to be a gangster, named Zanza, but he stopped when he becames friends with Kenshin. Even though he's no longer a gangster, Sanosuke still has a "bad-ass" attitude, with the word "BAD" on the back of his shirt. He has a strong sense of justice, but really really hates the government.
When he was little, Sanosuke was part of the Sekihoutai-gumi during the Bakumatsu war. The government had them all killed, so that's why he hates them so much. Sanosuke admired his Taichou, Sagara, so he took on his name. Kenshin reminds him of Taichou Sagara; that's why he admires Kenshin so much.
Sanosuke likes street fighting and has a powerful punch. He also tends to be always broke, so he tries to pinch some cash or free food off Kaoru or Tae-san. Sano is really fine, ne? He likes to take off his shirt a lot. (waaaaah!!!) He also likes to gamble and chew on fish bones.
another fish bone