Benimaru is a young son of a very wealthy, extravagant family. He is a professional fighter and part-time professional modeler who is very cool and confident in his abilities. When Japan held a tournament for their country's representative team in the King of Fighters, Benimaru entered and made it to the finals. Despite his experience, he lost to newcomer Kyo Kusanagi and earned second place. He and Kyo enter the 1994 KoF tournament with the third place contestant, Goro Daimon. Eventually, he befriends his teammates and joins them for the rest of the saga.
After the climax of The King of Fighters '97, Benimaru resumed his modeling career and went on a world tour. He returns to Japan before the 1999 tournament due to an invitation he seemingly received from Kyo's pupil, Shingo. In reality, both Shingo and him were actually set up to join the "special team" with K' and Maxima. During the tournament finals, he learns about NESTS, a syndicate that is responsible for Kyo's disappearance. After he helps Shingo escape from the crumbling base, Benimaru continues to track NESTS to try and find Kyo.
In the following year, Benimaru forms his own team with Shingo and his old friend, Seth. The agent also brings their final teammate, Lin. Benimaru hopes to use Lin's abilities to help his search for Kyo. In his team's ending, he saves Lin from Ron. After this encounter, Benimaru loosely trusts members from the Hizoku.
Regardless of his search's results, he meets Kyo again in 2001. Looking to relive their glory days once more, he teams up with the old Japan Team and Shingo. Each member goes their separate ways after the tournament's climax.
After he bails Shingo from a false arsonist accusation, he teams with him and Goro in the 2003 tournament. In KoF XI, him and Duo Lon are invited to Elisabeth Blanctorche's mansion. There, they discuss Ash Crimson's thievery of Chizuru's powers, the existence of Those From the Past, and their experiences during the 2003 tournament. The trio forms the Rival team and track down Ash. They find him after he steals Iori's powers. Benimaru sees Shingo and Kyo's beaten states and threatens Ash for an explanation. Before either members can interrogate him further, Ash teleports away and warns that Kyo will be next.
Deciding to let Duo Lon do as he please, Benimaru returns from overseas to Japan. He first visits Chizuru to tell her about what happened in the last tournament, both aware of the dangers that come with Ash's new abilities. Excusing himself to meet with his teammates, he visits Shingo to learn the details of what caused Kyo's hospitalization. Goro arrives and they catch up during the meeting. With the current state of affairs and the invitations from "R" passed out, he and Goro decide to reunite the old team for the tournament.
In the KOF XIII ending, he and Daimon both watch Kyo as he fights once again with Iori to an unknown result.
Benimaru, while sometimes outspoken and flamboyant, means business in battle as he's very proud of his skills and doesn't want anyone to look down on him for his good looks. He also respects ladies though he tends to be more than a flighty flirt. Although he seems to have an indecisive mind, Benimaru has a heart of gold. His loyalty and respect can go a long way.
Despite his American heritage, he carries many Japanese mannerisms. Though he would never openly admit it aloud, his pride as a professional fighter was shaken when Kyo beat him before 1994 and he secretly trains for a rematch.
- His character was loosely based on Jean Pierre Polnareff from JoJo's Bizarre Adventure.