Ben-K (ベン－Ｋ) is a robotic member of the Gravilian Empire and the fourth opponent that confronts U-1 in Gitaroo-Man. He is ordered by Zowie to intercept U-1 and Puma in space and catch them before they land on Planet Gitaroo. Not much is known on him, as he is rumored to be an "expert in karate", "a deformed robot" and other such stories.
Before the game was released, Koei revealed his image and asked fans to give him a name. Ben-K was the winner and the name was submitted by Tomohiro Maruyama. The name was chosen for its unique naming structure; it was also chosen since its standing posture roughly resembles the historical figure it got its namesake from.
In the Japanese version, he is voiced by Daisuke Tōjō (although his voice is heavily distorted).
U-1 and Puma first encounter Ben-K as they enter the warp hole to Planet Gitaroo. His first form is a giant hammerhead shark and he chases the Woofer Jet through the warp. U-1 and Puma are panicked by the sudden attack and U-1 can't transform into Gitaroo-Man, making the entire encounter a fast and furious dodging session. Players cannot regain their life so they have to survive a minute of inputing button combinations.
As they exit the warp, Ben-K bites the tail end of the Woofer Jet and they land on a space satellite near Planet Gitaroo. Seeing Ben-K change into his bipedal form, Puma transforms the Woofer Jet and U-1 transforms into Gitaroo-Man. Compared to the previous stage, the tempo is much slower and there aren't many buttons for dodging. However, the Phase Bars are the longest in the game and it may take some time to adjust to the bar's new length. For the Charge phases, U-1 tells Ben-K to "look over there" and tries to run away on the satellite. Ben-K falls for U-1's trick until the phase before the finale.
Ben-K's Gitaroo are the turntables pecs in his transformed form. When he's defeated, U-1 blasts him away and he disappears into distant space as a white star.
- used in Stage 4
- A techno, hip-hop song with several fast beats. Can't be played in Versus Mode.
- 'Nuff Respect, featuring NAHKI
- used in Stage 5
- A slow-beat, reggae, Jamaican styled song. It features English lyrics in the background, most likely improvised by NAHKI. U-1's Gitaroo changes its sound to be more like a synthesized electric guitar.