Vampire Knight vol. 2 - Matsuri Hino
Yuki and Zero go into town to do some shopping for the Headmaster, and they are attacked by a fiendish vampire called a "Level E". Two Night Class students, Takuma Ichijo and Senri Shiki, come just on time and slay it, and invite Yuki and Zero to their dormitory at midnight to find out why they killed one of their own kind... (courtesy of Goodreads)
Volume 2 of Vampire Knight is really Zero's story. He is a truly tragic figure. We learn at the end of volume 1 that when vampires attacked his family, Zero was bitten and is slowly becoming a vampire. Poor Zero. No one hates vampires more than him. Yuki promised to someday kill Zero if he gets out of control. Now we learn just how bad Zero really has it. He is a "Class E" vampire and will slowly lose all sense of himself. Yuki and Zero encounter such a vampire and it is truly terrifying.
Yuki sacrifices herself for Zero, in more ways than one. She isn't in love with him - or actually, I think she is, but she doesn't know it. I'm guessing that Yuki sees him as a quasi-brother and best friend. She will do anything to help him, even if it means killing him. Creative, giving Yuki comes up with some other solutions to save Zero's sanity, at least temporarily.
The Kaname/Yuki relationship is somewhat on the back burner in this volume. We still get a few moments where we realize how much Kaname cares for Yuki. She idolizes him and she is obviously very special to him. It's not entirely clear to me just how "in love" he is with Yuki. I think this will become clear as the volumes continue.
Another great volume that left me wanting more...