What is the plot for vampire knight?

For Season One of Vampire Knight:The story starts out when Yuuki is just a young girl and she is in the middle of a snowstorm and a "bad" vampire as she puts it, comes to try to eat her, thus frightening Young Yuuki and her savior (Which happens to be Kaname), kills the "bad" vampire and Yuuki--Being young--takes his hand. Fast forward 10 years, Yuuki is now 15 years old and she and her friend, Zero Kiryuu are the "Prefects"-which is just an alias for their real roles as Guardians for the Night Class, whom are all vampire's lead by one single pure-blood amongst their rank and that pure-blood is Kaname Kuran. That's just the first episode... 2 episodes later, in episode three, Yuuki finds out that Zero is a vampire who was bitten by the "Madly Blooming Princess" Hiou Shizuka, who comes to the academy as Maria Kurenai. Then later in the episodes (around 9-ish), Zero's twin brother, Ichiru appears as the bodyguard for Shizuka's body until Shizuka can regain enough strength. Eventually, Shizuka wakes up and lures Yuuki in to keep her part of the bargain. Zero interrupts and tries to kill her, but fails. This entire season is based on Zero getting his revenge on Shizuka, but he doesn't (due to Kaname getting to her first).

The Second Season: This season is based on getting back Yuuki's memories and protecting her from Kaname's resurrection bringer, Kuran Rido, whose son happens to be Senri Shiki. This all leads up to the final battle where Zero kills Rido to save Yuuki from a horrible destiny.