Toramaru is a large biker gang led by Chikage Rokujou that is primarily based in Saitama. They act as antagonists during the Hollywood and Toramaru story arcs but have since taken on a more passive stance in the story due to Chikage's friendship with Kyouhei Kadota.
Not much is known about Toramaru's history before the start of the series. They appear to be one of the more charismatic biker gangs within their area. Although there are a few hotheads in their group, they generally do not start much trouble beyond the usual noise complaint unless provoked. Toramaru's members have their own unique moral code, being against certain iniquitous behavior, such as refusing to harm children and, under Chikage's orders, refusing to harm women as well.
A few members, bored and looking to make a quick buck, discover Max Sandshelt's ten million yen bounty on the Black Rider and decide to look into it against Chikage's orders. They split up and start combing the city for Celty, and one group comes across Mairu and Kururi Orihara, who are also looking for her. When they begin harassing the two girls, they are thwarted by the timely intervention of Kyouhei Kadota and his crew. The Toramaru members give chase to the van gang across the city, occasionally attempting to attack the van with whatever they happened to be carrying at the time, mostly crowbars and pipes.
Meanwhile, the other half of the group manage to track down Celty and begin chasing her across the city as well. The groups eventually reunite and attempt to drive Celty and the van gang into a corner. Kinnosuke Kuzuhara and several other members of the traffic police intervene but only manage to take out a fraction of the group.
Toramaru eventually corners Celty and the others but, as they close in, Ruri Hijiribe appears behind them and attacks. Egor also appears, bursting out of a sack that Celty had been carrying the entire chase, and joins the fray. Egor and Ruri defeat the Toramaru members and force them to retreat. Bruised and humiliated, a few members afterward attempt to beat up Shizuo to vent but only end up getting sent to the hospital.
At some point between volumes, several Toramaru members, along with various friends and family members who are not in the gang, are attacked by remnants of the Blue Squares led by Aoba Kuronuma posing as members of the Dollars. Many of them were injured and hospitalized and in retaliation, Chikage and several others come to Ikebukuro looking for payback.
While the gang begins beating up Dollars members across Ikebukuro, seeking information on the group's leader, Chikage singles out Kyouhei as an influential member of the gang and challenges him to a one-on-one match. Kyouhei brings the fight to Raira Academy Field Two, where a student Dollars member nearby alerts the rest of the gang. While the two fight, a few rogue Dollars members attempt to use Chikage's girlfriend, Non, along with a few of her friends, including Rio Kamichika, as hostages to get him to back down. Kyouhei and Chikage have won each others respect by the end of their match, and the hostage tactic fails when Walker Yumasaki intervenes to save the girls. Several other Toramaru members join the fight to ally with the Dollars against the kidnappers, and the brawl grows more chaotic when Celty Sturluson, Vorona, Anri, and even Shizuo arrive. Shizuo takes out the lead kidnapper, causing the others to back down, and Chikage orders everyone back to Saitama.