Smash Girls

Overview:
A port city located on an island in East Asia... Koto. Divided into thirteen administrative districts,
beneath Koto's bustling surface lies a dark underbelly comprised of slums, black markets, cults, and assassins...

And then one day, the twelve most powerful gangs suddenly vanished,
leaving only the Kyoukakai Association, which consists of a mere two members: a white-haired girl and... a penguin.?