Renji is one of the main characters from the manga/anime Bleach. He is the lieutenant of the 6th Division in the Gotei 13, under captain Byakuya Kuchiki.
Renji has long crimson hair, usually kept in a high ponytail, and his entire upper body is covered in really cool tribal tattoo work. It appears that with every achievement Renji attains, the number of tattoos on his body increase as well, starting from his early days as a Soul Reaper candidate until when he becomes Byakuya Kuchiki's lieutenant (at this time his tattoos now cover his entire back).
These tattoos match those of Zabimaru in its manifested state (Zabimaru is his zanpakuto).
As far as his personality goes, Renji is about as eccentric as any other Soul Reaper. He varies from smug and cocky in his first appearances to downright angsty and depressed after his major defeats. But he shows himself to be an incredibly serious and determined fighter when confronted with an actual challenge. Willing to fight, kill, and die for whatever he believes in, Renji is a dangerous man to those who stand in his way. He is similar to Ichigo Kurosaki in many aspects, and the two are mistaken for brothers in the anime's Bounto arc.
Another cool and rather funny thing is his nick name, Red Pineapple, referring to his crimson hair kept in a pineapple top-like ponytail. During a filler arc before the invasion of Las Noches, Renji wears a shirt with 'Red Pineapple' printed on the front, supposedly bought by Ichigo as a joke. He's even referred as "Aka Pine" during the Shinigami Cup segments.
One of his best friends is Rukia. He grew up with her in the 78th district of Rukongai. But please, please just don't think of them as a couple. That's just... wrong.
Ok, I would call him.. stylish and cool. I really like his tattoos and hair style, BUT he's just too arrogant sometimes. The first time I saw him, I wished he would just drop dead. Yeah.. he was such a jerk. After episodes 30+ though (especially after his past in Rukongai was revealed), he was a much more likeable character. Well, he was still cocky, but he changed quite a lot from his first appearance.
Personally though, I like Ichigo a bit (or a lot) more (okay, now I KNOW this is gonna get bad ratings :D). Renji is pretty tough, but Ichigo could kick his butt any day of the week :D.
I could tell you a lot more about him, but I don’t want to make any spoilers. The best thing would be for you to watch the anime (or read the manga) and see him yourself. Don’t listen to all the jerks who say Bleach sucks. It doesn’t. Oh well, we can’t judge people’s feelings... but at least see for yourelf if you like it or not. :) I could go on about this forever, but considering the fact that I’m just procrastinating homework here, I’ll just call it quits :)
From the 'Shinigami cup' (at the end of Bleach episodes):
Abarai Renji : What the hell's goin' on?! I'm going to see what's up! Hey, where's my Zabimaru?! Have you seen it, Hinamori?
Hinamori: Now that you mention it, I think I saw someone cutting pickles with it.
Renji: Howl, Zabimaru! Cut those pickles to shreds!
Ichigo: Hasn't your personality changed a lot lately?
Renji: My power now is 5 times more than the last time we fought.
Ichigo: Hey, I trained and got 10 times stronger.
R: Then I'm 100 times that!
I: I'm like friggin' 2.000 times more!
R: Actually, I meant 10.000 times!
I: Then I'm 100.000 times that!
R: No, I'm 1.000.000 times!
I: Well, I'm infinity times anyway!!