QUOTE (Tecumseh @ Feb 11 2016, 01:57 PM)

Critias is exactly right. (I ran a three-year campaign in Puyallup and practically memorized the relevant portions of the source material.)
Zednark, do you have Seattle 2072? It has seven dense pages at the back of the book that goes into this in quite a bit of detail, plus additional references through the sections on various neighborhoods/districts. I've leaned on it heavily for my campaigns.
Tacoma has been Yakuza territory ever since the Night of Rage, when the Yakuza swept in and bought a bunch of torched properties for pennies on the nuyen. (This was detailed in the original Seattle Sourcebook. I don't know if it's been discussed extensively since then.) Recently the Vory have kicked in a foothold along the docks, which they are used to expand further into Tacoma and into Auburn.
It's also important to know that the syndicates are not necessarily unified internally. There are three different Mafia familes, each with their own turf. The same is true for the Yakuza. For example, the Kenran-kai in Puyallup were formed from the survivors/refugees of Nishidon-gumi and Shigeda-gumi, which were split up after various assassinations and internal purges. Thus, you have Kenran-kai remnants that used to operate in the Shigeda-gumi's old turf, namely Everett, Snohomish, and Auburn, plus the Redmond Barrens. You can bet that the Kenran-kai would love to crawl out of the drekhole that is Puyallup and back into their old stomping grounds, and maybe do some score-settling along the way. Long story short, broad strokes like "Mafia" and "Yakuza" can disguise interesting squabbles among the factions.
I do have Seattle 2072, as it turns out. A while back I got a lot of Shadowrun books off Craigslist on the cheap, and I mean a lot. They mostly just take up space, as I run 5th ed and they're mostly 3rd and 4th ed stuff, with 1st and 2nd oddments thrown in. Thanks for the reference.