There's love at first sight And then there's love at first sighting. Don't know the difference? 20th Century Girl is here to make it clear as one of its two besotted teen heroines, Yeon-du (Roh Yoon-seo), becomes thoroughly enamored of their new classmate Hyun-jin (Park Jung-woo) the moment she spots his silhouette in the doorway of her mother's clothing shop. Sometimes, the heart doesn't even need eye contact! Compare this irrational behavior to that of her best friend Bo-ra (Kim Yoo-jeong) who takes a little longer to warm up to his best friend Woon-ho (Byeon Woo-seok). With tearjerking results.
Because these two girls are destined to get these two boys mixed up. They both will fall hard for Woon-ho but with Yeon-du abroad for a heart operation and Bo-ra trailing the wrong guy unknowingly on her friend's behalf, plenty of seemingly innocent hijinks will tangle up Bang Woo-ri's YA yarn gang fights and falling plums, first kisses and drunken confessions. But... since Bo-ra can't square her divided loyalties, you're not sure who will end up with whom. Or for how long. You see, the trouble with acting on your friend's behalf in high school, at least, is that your actions may be misattributed and misinterpreted. Especially when you're too embarassed to say how you really feel. Well, maybe not just in high school. In K-drama, too.