Kong-Shim has always lived in the shadow of her older sister, Kong-Mi—beautiful, polished, and successful. Considered awkward and unattractive by her family, Kong-Shim dreams of escaping her stifling life and studying art in Italy. To save money for her goal, she rents out her rooftop room to An Dan-Tae, an eccentric, hot-tempered pro-bono lawyer with a mysterious past. This chaotic living arrangement turns Kong-Shim’s world upside down as Dan-Tae crashes into her life with both trouble and unexpected kindness. Meanwhile, Kong-Mi, ever ambitious, is climbing the corporate ladder at a prestigious law firm, unapologetically using her looks to get ahead. As Dan-Tae becomes entangled with a wealthy family searching for their long-lost heir, Kong-Shim finds herself caught in a love triangle between him and the kind-hearted but privileged Joon-Soo—unaware that Dan-Tae may be the very grandson the family is searching for. While Kong-Shim starts to come into her own at her new job (ironically hired for being “plain”), her sister decides to pursue Joon-Soo for his wealth, turning the siblings into romantic rivals.