Framed by soft music and sentimentality, “Madeleine” kicks off with the cute chance meeting between its twenty-something romantic leads, who have not seen each other since high school – quiet college student Chi-suk (Jo In-seong) is an avid reader, while Hui-jin (Shin Min-a) is a bubbly hairstylist. The aggressive Hui-jin wastes no time in inserting herself into Chi-suk’s schedule, and she suggests that they go steady for one month in the style of a walk-away car lease – if they have not fallen in love by month’s end, they will go their separate ways with no questions asked.

Though Chi-suk is at first reluctant, he acquiesces to Hui-jin’s request and pretty soon they are spending quality time together, such as taking bike rides in the rain, preparing meals at her place, and playing computer games at the local Internet café. However, as the end of the month-long period nears, some unexpected complications arise that place the budding relationship in jeopardy.

One, Chi-suk runs into Sung-hae (Park Chong-a), another girl he had a crush on in high school, who has since blossomed into a beautiful and vivacious rock singer. In addition, it seems that the feelings were mutual, as Sung-hae is still in love with Chi-suk. Second, Hui-jin’s past catches up with her, forcing her to make some very tough decisions that leave her resigned to letting Sung-hae have the man of her dreams.