looks
sharp like an edge of a samurai sword
Every anime has a pretty boy, and Jin is undoubtedly the pretty boy of Samurai Champloo (though decidedly more manly than the majority of his ilk). Fuu describes him as "a little attractive", but the manga takes this a step further with women outright 
Physically, Jin is tall and lanky, with angular features and a narrow face. He is very pale -- probably one of the palest in the series -- which contrasts with his long, dark hair. It's usually pulled back in a thin ponytail, though we get to see him once or twice with it loose. For some reason, it appears a lot thicker when it's down.
And of course, he also wears a small pair of glasses, which apparently have nothing to do with his eyesight -- they're just there for looks. (And who can blame him?) They are an obvious example of Champloo's clever use of anachronisms -- those classy frames are obviously not something you would see every day in pre-modern Japan. They attract the interest of a pawn shop owner, much to Mugen and Fuu's amusement.
Jin's outfit is that of a typical samurai, consisting of a gi and hakama. The gi is dark blue with a 4-diamond mon, or family crest, on the back, shoulders, and front. A white rectangle-shaped sheet is tucked into the gi near the waist. (I have no idea what this is. Feel free to clue me in.) His hakama is black, and underneath he wears traditional straw zori and tabi socks. His paired swords (daisho) are tucked neatly into his dark red obi for easy access. He wears a bracelet made of blue Buddhist prayer beads on his right wrist. Occasionally we see him don a large straw hat that shadows most of his upper face, preserving his anonymity.
As a young boy and teenager, his bangs were shorter and he lacked the glasses, but otherwise he generally looked the same.