Kaname has lived so many years more than Zero so when he says that Yuuki is his ONLY ONE (or better when Hino puts that character to say this) it has a totally different gravity, not to mention that Zero never stated something similar … on the contrary he said when they parted that now he can move on with his life >> “So now I have nothing to worry about anymore … I can go do my job…”
Hino has made it so crystal clear (throughout the story but also in her fanbook) that Kaname’s love for Yuuki is beyond limits … A few lines for Kaname>>
- “Taste in women: A single minded girl who keeps waiting for me in the snow”(while Zero's taste is "cool older women [flat-chested women are out of question]
- “The one who warms his heart … is the tender existence … that is HIS ONLY ONE.”
-“ Juuri kisses Kaname goodbye and leaves Yuuki in his care. After this Kaname’s ONLY REASON FOR LEAVING is Yuuki’s existence.”
-“ My arms exist to hold only ONE person. I can’t hold anyone else … sorry.”
- “Kaname to Yuuki: “You are my fiancée” >> Kaname tells Yuuki that they are LOVERS.”
- “… Yuuki and Kaname were born to marry each other…”
-“I love you more than anyone else in the entire world.”
-“Yuuki please ONLY YOU” …
I’ll stop here cuz I think the picture is crystal clear …
Furthermore Zero knows Yuuki only for four years whereas Kaname for all her life if not even before …
Conrad Weller wrote: yume pair is established since yuuki and kaname were children and kaname only has his eyes for yuuki.so it is useless pairing kaname with anyone. yuuki and kaname pairing is stated since ch 1. it is mutual.
Kaname and Yuuki is officially a couple … they have exchanged promises to spend the eternity together … they expressed mutual their love so many times … Hino has officially deemed them as LOVERS in the fanbook as in the story as well.
So how it can be compared a non-existent possibility for Kaname to be with another woman except Yuuki with the potentiality of Zero to find EVENTUALLY a mutual love is beyond my imagination!
I’m not trying to downgrade Zero’s love for Yuuki but honestly putting Zero (a young boy who doesn’t know what he wants) and Kaname (an experienced and well grounded man) on the same boat is unthinkable.