Yuki & Kaname

As the first year Day Class student and school guardian at Cross Academy, Yuki shows a strong personality. It's known that Kaname saved her on snowy day when she was 5 years old and a degenerated E class vampire attacked her. Therefore the bound she developed towards him is quite deep and important to her being after all, the very first memory she has from a past life she doesn't remember anything about.

Yuki later learns that her gentle savior is a special vampire on his own kind, a pureblood. Although she doesn't seem shocked and quickly dismiss the thought as she thinks it won't change her opinion on Kaname. After all, Yuki feels a huge admiration and idolizes Kaname; she also seems to have a crush on him. However Yuki is no fool, and grows fast as the mystery around her is slowly revealed.

As for Kaname, Yuki is on his own words "her dear girl". we can say he keeps Yuki as her precious ward. Since they supposedly first met Kaname as always kept an eye on the little girl and watched out her every step, she is so important that on several occasions he left the Ichijou's keep and went straight to Chairman Kurosu's house to check on her well being.

A decade later, Yuki being the young woman she is now attires more and more Kaname's attention on the most close to love level Kaname is willing to show. However once more, Kaname is a vampire and what is more important, a pureblood. He cannot allow himself to step closer to Yuki and risk to hurt her... or even curse her forever by drinking her blood.

This one fact demonstrates how Yuki is important to Kaname, although most recent chapters could change this point of view and reveal the real purpose in Kaname's scheming