Kyo

There is also Kyo Kusanagi from the King of Fighters video games.

This name is also used by Kyo from Samurai Deeper Kyo as well as Kyo from Zatch Bell.

Kyo is the name of an amazing lead singer from a Japanese rock band called Dir-en-grey.

Of course, in Kyo (Dir-en-Grey)'s case, the name Kyo is derived from the first symbol for Kyoto, which is where he is from.
I've never heard this name used as a given name in any other circumstance in real life, so naturally it's unique to...eh...Kyo. It's a lovely name, I must admit though, one of my favourites.

This name has become more well-known thanks to the manga and anime Fruits Basket which has a character by the name of Kyo.