This Character Bio was written by me.
Seiyuu: Megumi Ogata
Yukito is Toya's best friend(and subsequent lover), and he rides his bike with Toya to school everyday. The only reason that Sakura accompanies Toya on his way to school is so she can see Yukito, whom she has a major crush on. He's gentle, kind and carefree, just like Sakura, which is probably why she likes him so much.
However, after Sakura collected all of the Clow Cards, Yukito's secret is revealed - he's actually Yue, the other guardian of the Clow Cards whose symbol in the Moon. Sakura had to defeat him in the Final Judement in order to gain possession of the Clow Cards. After the battle, Yue and Kerberos changed back into their hidden forms(Yue back to Yukito, and Kerberos back to Kero.) They're able to change back if Sakura needs their help, though Yukito doesn't retain any memory of being Yue.