You're Yuki's twin sister, you're the unloved twin since Yuki is the love one. Your older brother love you and will always love you since your parents Haruka and Juri are sibling too.

Your parents neglect you and pay attention to Yuki. The Kuran family was pureblood royal vampire, Kaname always choose to love you in his heart. He wanted be fiance to you only not to Yuki.

Now it's been now, you are the real pureblood princess not Yuki, Yuki may pureblood but she is not a pureblood princess. Kaname being pureblood vampire king the one rule vampire to create.

Yuki become human when your mother erased her memories childhood and sealed her vampire side. You also got sealed too and erased, Now you and Yuki part prefect with Zero Kiryu.

You saw Zero had feeling for Yuki while Yuki had feeling for Kaname, but Kaname doesn't had feeling for her and he had feeling for you only. He's your fiance since he broke the bond betweem him and Yuki engaged broken to make him engage you.

Now that your uncle Rido will be awake to go after you and Yuki's blood. Kaname turn Yuki first when she got remember and got her vampire side return then Kaname turn you as you remember and got your vampire side return.

Kaname only protect you and he trusted Zero to protect Yuki from Rido. The night class protect you and Yuki.