Cooperators is the seventieth chapter in the Vampire Knight manga.
Yuki walks the streets questioning people on the whereabouts of the vampire who got away from Zero the night before. Meanwhile, people are noticing that the streets are getting dangerous. Yuki heads into a vampire only bar and shows the bartender a poorly hand-drawn picture of the suspect. She asks the bartender about a rumour of a man kidnapping children. The suspect stands up identifying himself. When he realises she is a Pureblood vampire, he makes a run for it. Yuki slings her handbag and hits him in the back part of his head causing him to fall face flat. As she states that she hit him too hard, leaning over her unconscious target, she notices and greets Zero leaning against the wall of the bar. Zero tells her that she went after his prey. She snaps back that Zero let him get away but mentally asks if Zero is ok. Zero comments how a lot of trouble has stirred up quickly and that Yuki should realise it is Kaname's fault. He walks away and tells her to have her bodyguard hunter take the suspect.
Shiki directs Rima's attention to a troubled model, who was scared by a man who followed her and told her she was unappetizing. Shiki notes that troubles have increased and that the aristocrats should be watching out for that. Rima says that Kaname is scarier to the nobles and they're worried because they don't know his motive and the other Purebloods are just looking on and that it must be tough for Yuki.
Maria's parents receive a notice via the Hunter's association from Yuki Kuran, her father asks what kind of person Yuki was and Maria recalls that Yuki was easy to talk to and always with Zero. To their surprise, Yuki arrives to talk to Maria, asking if Maria remembers her. The vampires discuss Yuki's letter and think it is impossible for her to take Kaname's place. Shiki and Rima complete their modelling shoot when Yuki arrives and she thinks she is going to do something that Zero will hate.
Zero talks to Kaien at the Hunter Association headquarters about Yuki being able to freely come and go. He asks if Kaien is using her as bait to lure out Kaname and says to just send Yuki to find Kaname because Yuki is an eyesore. Kaien says that Yuki will not go after Kaname as she has something else to do (protect the agreement between hunters and vampires), Zero asks what can she do alone and Kaien implies that she is not alone. Yuki comes in with a request and Zero leaves.
Zero visits Aido who is forlornly sitting in his cell. Aido asks him what he wants, Zero says he came to tell him that Yuki is up to something. Aido instead thinks that Zero is taunting him wanting to see Aido consumed by hatred for Kaname and Yuki. Aido says he refuses to become like Zero no matter how difficult it is, but he is troubled by having dark thoughts.
Yuki tells the vampire Nobles she wishes to reunite the Night Class because she alone cannot protect the agreement between the vampires and hunters. The vampires says as a Pureblood, she doesn't need to ask them for permission, Yuki disagrees and says she wants their cooperation. She wants the Night Class to be her comrades who protect the agreement with her and that she wants to make allies of the nobles too.
The vampires express concern about Kaname and then note that Yuki has no comrades. Shiki and Rima arrive to disagree and state they are going to collaborate. However upon realising that Aido was not joining them, they declare they cannot trust Yuki not to use her Pureblood powers to control them. Aido enters and says that she will not do something like that and that he believes in her and asks them to cooperate.
Sara is amused as she reads a letter that requests Takuma to be head of the Night Class since Kaname is no longer around, she smiles and states that she wants to go to the Night Class with her adorable servants.
Characters in order of appearance: