Chiba
Just as a warning, this section contains spoilers up to fairly recent manga chapters, so read at your own risk.

Chiba is an eccentric ramen chef-in-training who reunites with Ryuusuke (who happens to owe him money) at a baseball game (which turns out... well, violently). After some persuasion, he agrees to be BECK's vocalist, mostly so he can "meet women". His passion for the band comes through many times, showing the most sheer enthusiasm when their first CD was unveiled. After the band's breaking at Greatful Sound, Chiba goes into "hiphop training" and later, helps convince Ryuusuke to come back to BECK. Later on in the manga, Chiba is urged by an old friend to enter into a rap battle competition; despite his eventual defeat, his resolve with the band is strengthened. And now, a little backstory: Chiba was bullied as a kid, so he took up self-defense (which comes in handy for Koyuki). As far as academics go, Chiba is at the top of his class at his school. In short, Chiba just rocks.

BECK manga-ka Harold Sakuishi has stated that one of the two characters that resonate with him personally is Chiba (the other being Koyuki).

The BECK anime has Chiba portrayed by Shintarou Oohata, with his singing voice provided by lead MC Tatsuzo of YKZ. More recently, the BECK live-action film had Kenta Kiritani representing Chiba.

Other facts:

Name: Chiba Tsunemi
Age: 16 (at manga start)
Family: Brother, Mother, Father (gone)
Position in BECK: Vocals (Rapper)

Chiba is possibly the band's most emotionally charged member, wearing his thoughts and (most often) feelings on his sleeve. Bullied as a child, he took karate and is now an intensely good fighter. We initially meet him at a baseball game, where Ryusuke hides because he owes Chiba money. Eventually, because of his pure energy and persona on stage, Chiba's selected as the frontman for BECK, the rapper. When he feels he isn't improving as much as the rest of the band, he'll go out and enter contests or freestyle with other artists to refine his own sound.

Quick facts:
- The band's best fighter, by far.
- Likes cooking, even if it's not very good.
- His brother has a handicap and Chiba is very protective.
- Very touchy about the band and his own ability.
- Most often, Ryusuke owes Chiba money.
- Favorite band is Generation 69.

(Some facts from Rock and Roll, with permission.)