Yuki Kuran fancys her fiancee/husband Kaname Kuran.
Yuki Cross's theme song from Vampire Knight is just called "Yuki Cross's theme". It's the third song down listed in Vampire Knight: Original Soundtrack.
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vampire knight episode 7
Cross Yuki's eyes in Vampire Knight are depicted as a reddish-violet color. This unique eye color is a significant characteristic of her vampire lineage.
Zero Kiryuu
In the manga but not in the anime.
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Yuki has a flashback about Zero joining their family in the second episode of Vampire Knight. In that episode, Yuki remembers how Zero was taken in by her father and brought to live with them after losing his family to a vampire attack.
In the end of the anime, she chose Kaname.
Zero promises to come kill Yuki when the time will come and Yuki will waiting for that since now she was kanames sister which makes her a pureblood vampire and then yuki goes with kaname.
Yui Horie is the voice of Yuki Cross/Kuran. Although Yui doesn't really look like the character Yuki.
The Forty-Third Night: "Vampire Night" Where Yuki and Zero finish off Rido and then Zero turns his gun on Yuki.