Osorubeshi! Otonashi Karensan.

This is a light-hearted, typical high-school "girl-has-crush-on-boy" type of drama. The main character, Otonashi Karen, was only used to gazing at her crush from a distance, until one day she misinterpreted his line while eavesdropping, turning her usual, timid self into a fancy "Barbie-doll" to attract his attention. The guy, of course, found her ridiculous and unbearable. Nevertheless, this drama traces the "fairy-tale-like" yet somehow sweet process of Karen's devotion to this guy. Each and every episode also shows how Karen's enthusiasm momentarily melts his heart, leaving him smiling with pure amusement, which indicates his growing fondness towards her.