WANTED: Ken & Yohji
Though the three leaders of Estet, also known as SS, were killed at the end of [the anime series], there is still unrest in the branches of Estet that were left. Wanting to destroy their leaders' murderers, several Estet members have spread to all corners of Japan to find them; however, they have not yet made a move, and Weiss, Kritiker, and Schwarz remain ignorant of their plans that may soon be put into motion. They remain as they were before -- mere assassins, with no true motive.
However, Kritiker has not overlooked the action and skill Schwarz displayed throughout the battle against Estet and the Takatoris, and admire their talent. Kritiker assumed Estet was merely sleeping, not dead, and decided to merge Schwarz in with one of their existing assassin teams.
Guess who picked the short straw? That's right-- Weiss.
Now, the members of Schwarz and Weiss have to deal not only with their own team's problems, but they also have to peaceful coexist since they're living together. This should be good.