@Masaki Haruna O,O
Okay~
The reason why the Yakuza was brought up is that its one of the ways Anderson doesn't have to actively fight against other gangs and Skill-Out. His mother, being a Yakuza Princess, dotes on Anderson in the way of protection and annual subsidies. Should the need ever arise, she could sent members of the Yakuza clan against whatever foe might be picking a fight with Coercion (the syndicate Anderson runs). It is also said that a number of Anderson' agents are either currently Yakuza or ex-Yakuza.
The Yakuza clan also make a yearly appearance on Anderson's birthday, surprising him where ever they feel like, often leading to some very awkward situations.
Anything else you need?
Also, the duck Kazeno is currently in possession of is part of the Yakuza. PLOT TWIST O_o