OVA
Description
Tom Tanaka, an old friend and senior of Shizuo Heiwajima, first met him during Shizuo's middle school years. Witnessing older students attempt to bully Shizuo only to be beaten up, Tom approached Shizuo with dual goals: learning to avoid angering him and enlisting his help to move the injured seniors to a hospital. He bought Shizuo dinner and advised dyeing his hair blond to cultivate a reputation deterring future harassment. When senior delinquents later pressured Tom to deploy Shizuo as a "rabid dog" combatant, Tom refused and reprimanded them for ignoring Shizuo's hatred of violence. After the seniors attacked Tom to trap Shizuo, Shizuo intervened. Tom explained that despite lacking fighting skills, he would never exploit Shizuo's strength due to his aversion to violence, securing Shizuo a period of peace until their high school separation—later undone by Izaya Orihara.

Years later as adults, Tom encountered Shizuo struggling with employment and hired him as a bodyguard for his underground debt collection agency. Tom's ability to manage Shizuo's volatile temper and leverage his strength made him Shizuo's permanent employer. Shizuo intimidates debtors using his reputation to avoid unnecessary violence, though he often resorts to force. Tom's agency operates independently from banks and, in light novels, collects debts for an online dating site.

Tom possesses unparalleled knowledge of Ikebukuro's gangs, exceeding even Izaya Orihara's expertise. He dresses in a suit with a striped unbuttoned shirt and dyed dreadlocks, projecting a sharp yet practical appearance for confrontational work. Reserved and laid-back, he remains calm during Shizuo's destructive outbursts and ranks among the few capable of de-escalating his anger without provoking rage.

Across story arcs, Tom and Shizuo handle debt collections. In the Saika Arc, Tom arranges an interview between Shizuo and reporter Shuuji Niekawa, warning Shuuji against provoking Shizuo. When Shuuji angers Shizuo, Tom distracts and calms him. Later, they confront debtor Takashi Nasujima, with Shizuo breaking in and incapacitating him. During the Hollywood Arc, Tom witnesses Shizuo attacking assassins Egor and Hollywood after Egor mishandles Shizuo's briefcase. Tom later approaches the injured Egor to offer sympathy and a Shizuo warning. He also advises the Toramaru gang against unnecessary fights, unintentionally angering them and triggering an altercation damaging Shizuo's clothes.

In the Toramaru Arc, Tom and Shizuo encounter Akane, who tries to stun Shizuo under Izaya's false information. After Akane collapses with fever, they take her to Shinra's apartment. Upon recovery, Akane explains the misunderstanding, and Tom supports Shizuo's decision against immediate retaliation. Later, when Shizuo is framed for murder, Tom accepts his silence without pressing for details. During the Daily Life Arc, Tom advises Shizuo on non-violent intimidation after a debtor provokes him. At Russia Sushi, Tom notices Vorona, attempts flirting in Russian despite Denis's guidance, and fails. Denis assigns Vorona to assist Tom and Shizuo; she accompanies collections, often incapacitating debtors before they intervene. At Kishimojin Temple, Tom deduces Vorona's romantic interest in Shizuo after observing Akane confront her.

In later spin-offs and novels, Tom's role expands. "Caged Wonderland" depicts Tom, Shizuo, and Vorona relaxing at a bar when Tom's boss assigns a job involving Kita. After Kita insults Shizuo's brother Kasuka and Shizuo nearly kills him, Tom and Vorona leave Shizuo to handle the job. When Shizuo disappears, they search all night, with Tom contacting Kasuka for help. Finding Shizuo severely injured with a bull head and a nearby body, they conceal the truth from Kasuka and Simon, claiming Shizuo is sick. In "The Month of No Gods," Tom reveals Shizuo's whereabouts to Vorona during an incident. "Black Swan Wonderland" shows Tom collecting a debt from Dan, detecting a foul smell at the residence; he convinces a scrap-metal-seeking girl to leave before calling police.

"Dark Alice in Dark Wonderland" has Tom tracked via mysterious texts during a job. He and Vorona find Shizuo in an alley, with Tom luring him to safety. They take Shizuo to Tom's apartment, and with no alternatives, Tom contacts Kasuka to reveal Shizuo's condition.