Kasumi Kageyama

Kasumi is the class president of Yuuki and Zero's class. He seems to be a very strict and orderly person who would do anything to get what he needs out of life. He can be rather dramatic, shown when he agitatedly called Yuuki out on her poor grades. Kasumi seems to have a big crush on Ruka and gets flustered around her.

[Spoiler] Kasumi is one of the remaining students of the day class that remembers about the night class' secret and the events which took place in the Rido Kuran Arc. His mind was original erased, but he regained his memories after seeing Ruka (which reminded him of his love for her). [/Spoiler]

(Source: Vampire Knight Wikia)