This story is a favorite of mine.
To start a rich old man "picks up" a kid off the street and hires the Child to be a body guard. Since the job calls for a Boy and the now named Suh Hyun-Bin is a Girl already dressed as a boy. Hyun-bin now in high School and meets a person who makes him wish he could be true to his feelings. Add in the idea that the old man when to the trouble to raise Hyun-bin for more than a body Guard and You get a whirlwind for the next 7-10 years. This beautifully done story has had me crying and even laughing at times. Well worth the time to read and buy (if anyone knows where to get the official English translation that the author okayed, Please post it some where.)
Love in the Mask