Tom Tanaka

Tom Tanaka (田中 トム Tanaka Tom) is an old friend and senpai of Heiwajima Shizuo. He works as a debt collector, and later become Shizuo's employer.

Characteristics
Tom is usually seen walking around in a suit, but his clothing and his hair don't make him look too formal. This is probably due to his job as a debt collector, which needs him to look sharp and business-like but not too polite and friendly, as he often confronts people. It is likely that he works as an underground debt collector, and not for something like a bank.

He generally has a sort of reserved, laid back personality, and as harsh as you might expect an underground debt collector to be. He is usually calm, and is able to calm Shizuo down and make him stop without angering him and incurring his wrath.

Background
Tom and Shizuo met when Shizuo was entering middle school. Some of the older kids tried to pick on Shizuo, but were soon beaten up; Tom however did not pick on him, and the two soon became friends.

Much later, when both of them were adults, Shizuo was having trouble keeping a job. He finally found a permanent job that his brother, Heiwajima Kasuka gave him, until Orihara Izaya framed him for a crime and he was fired. Tom met Shizuo on the street, and decided to hire Shizuo as a bodyguard.

Thanks to the fact that Tom is able to control Shizuo and Shizuo's strength and destructive tendencies are actually a good quality to have in his line of work (instead of problematic like they were for his previous employers), Tom became Shizuo's permanent employer. Shizuo's job is to "basically beat up people who can't pay up," and generally to stay around Tom, protecting him. Tom also using Shizuo's name and reputation to scare people into paying their debts.