The Yakuza care about exactly one thing, and that's making money. If the rapist invaders aren't affecting the Yakuza bottom line, they don't care.
Once the invaders have ruined the entertainment districts enough that nobody goes there any more - which will take very little time - then they'll start mysteriously vanishing.
The Yakuza don't really exist all that much anymore. Government crackdowns over the decades have greatly reduced their size and scope. A good chunk of Japanese crime is done by immigrants nowadays. Same as all first world countries.
Is there much of a Yakuza left? If so, why aren’t they stepping in to take care of the problem individually?
The Yakuza care about exactly one thing, and that's making money. If the rapist invaders aren't affecting the Yakuza bottom line, they don't care.
Once the invaders have ruined the entertainment districts enough that nobody goes there any more - which will take very little time - then they'll start mysteriously vanishing.
The Yakuza don't really exist all that much anymore. Government crackdowns over the decades have greatly reduced their size and scope. A good chunk of Japanese crime is done by immigrants nowadays. Same as all first world countries.