#2: Huh...What a special kind!
#1: What's wrong, sir?
#2: This girl...she's so unpredictable and dangerous
#1: I've heard about that, sir. Are you going to consider her to our agency?
#2: Hold on! I've got one...more...left.
Brown, Blue, Red and Yellow go to missions as agents because Yellow made a deal between the 4 of them. 1 brutal, 1 carefree and 2 bloodthirsty girls go on dangerous missions together.
(That's just it. Not detailed, but I also didn't want it to be dramatic)