The future of Yuuki's relationship with both Zero and Kaname is revealed in the 日本漫画 upon which the 日本动漫 was originally based. Either read that manga, 或者 read the 答案 to 前一个 问题 on this site, which already summarise the events in the 日本漫画 after the 日本动漫 finished (and the events which happen in the 日本漫画 which were changed in the anime).