CLAMP (Mangaka group)

"Now that Sakura has proven herself as a magician, she finds that there are other unnatural forces threatening her town... forces linked, somehow, to two mysterious transfer students who've just arrived - one attracted to her brother, the other attracted to her! Li and Sakura may be friends now instead of rivals, but if there's a rival for Sakura''s affections, is he going back to Hong Kong?"--Amazon.com.