The Dakker (ダッカー Dakkā) is a criminal organization which was formed by the mysterious President D (who is revealed in the final episode). It is different from most tokusatsu series evil organizations, when its members are all humans; doesn't have any monsters, and outlandishly-dressed criminals.
An episode would generally have a single head criminal (the Boss), and a Bodyguard (a killers who assist the bosses), somehow terrorizing a group of people. Ken Hayakawa would happen upon this, and meet the bodyguard, which would lead to a demonstration of the latter's preferred skill, only for Ken Hayakawa to show that he was much better.
Under the leadership of Leader L, there are 29 regional bosses and 31 bodyguard. Each boss is responsible for committing different crimes, while each bodyguard has a different way of killing people. Some bosses and bodyguard styles themselves after a historical figure, and some also based on fictional characters. Under the bosses and bodyguard, there are ordinary gangsters.