Kaname: Why am I not a main character anymore? ._.

Yagari is apparently Zero's old vampire hunter master. A flashback shows that Yagari lost his right eye to save Zero's life, but not how. Before anything else can happen, Chairman Cross breaks up the confrontation.
The next day, Zero doesn't show up at class, worrying Yuki to no end. After carrying out prefect duties, Yuki heads to Zero's room to find him missing. She seeks out Yagari to ask him where Zero is, and the latter responds that he's locked up Zero somewhere in isolation. Before she can protest, he walks into the Night Classroom, having been assigned as the teacher.
The world's top vampire hunter teaching a class full of vampires is definitely NOT a perfect setup for super-tense-atmosphere. Yagari makes a veiled threat on Kaname's life, quickly earning him the animosity of Aidou and Ruka. As the class ends, he's given a dagger as a parting gift.

Yuki's still waiting outside, so Yagari lets slip the information that Zero's being held in the Chairman's guest room. She rushes there to find it unlocked, that he's willingly detained himself. Zero explains his fear of vampires; there used to be a beautiful nurse at his primary school… however, she was actually a vampire, and fell to Level E at a very bad time. When Yagari shows up to slay her, Zero pulls a Yuki (Jumps in between Yagari and the nurse saying she's a good person, etc.), and in order to save Zero's life Yagari loses his right eye.

Anyway, Yuki storms her way into the room, pulls Zero over to the bathroom, and says they should 'do it' in there. (Ooh la la~ xP jk We all know she's going to share her blood.) Giving in to temptation, Zero obliges. He immediately regrets it, and tells her that this is 'fake gold' and that she should abandon him. Yuki'll have none of that, and pledges herself for Zero's sake. (So sweet q_q)

TAKEN OUT OF CONTEXT XDXDXD

More biting! Ｏ(≧∇≦)Ｏ

On patrol, Yuki crosses paths with Kaname, who is the last person she wants knowing what she did. lol well, it's pretty obvious he knows, but hides it for Yuki's sake. After they part, Yagari shows up to goad Kaname, which results in the need to use his lighter again.

Next day, Zero doesn't show up for class, plus Yagari is late too. Yuki jumps at this realization, and sure enough she rushes to his room to find Yagari about to shoot Zero. Zero seems prepared to die, but as soon as Yuki shows up he grabs Yagari's gun and prevents his master from killing him. Yagari says that he really wanted to kill Zero since he was being all emo, and felt that he'd wasted his right eye saving someone who was so weak. With Yuki by Zero's side, though, it seems that Zero can fight on, so Yagari leaves him be. While leaving, Yagari tells Zero that 'that woman' is still alive.

Thoughts:
Well, ZeroxYuki fans are certainly getting their servings, xD. Granted, it's kind of sad, with Zero's fate sealed to become a Level E and all. :(
Despite Yagari's fierce appearance, it's clear he harbors sympathy for Zero. Not like I ever thought otherwise. Kind of sad for Yagari, though, he lost his right eye for Zero who has become a vampire himself.
Speaking of 'that woman' Yagari mentions at the end, it's gotta be the pure-blooded vampire that killed Zero's family! Not that I… know for sure or anything, just a hunch.