As a high school freshman, Oh Na Ri (Arin (Oh My Girl)) is determined to make her high school years the best they can be. But it’s not easy to make friends when you feel like a squid surrounded by a school of beautiful mermaids. Struggling to boost her own self-esteem, Na Ri sets out on a journey to better herself. As Na Ri begins to find her confidence, her naturally good nature draws towards her, a very special set of friends.  One of Na Ri’s childhood friends, Im Yoo Na (Hwang Bo Reum Byeol) is one of those girls who has everything going for her. A good family, gorgeous looks, and everything in between, Yoo Na is the type of girl every guy wants to date and every girl secretly wishes they could be. But despite it all, Yoo Na is incredibly happy. Surrounded by fakes and flakes, Yoo Na craves the type of connection that only comes through true friendship. Realizing that Na Ri is the only person in her life that wants nothing more than to be her friend, the two girls begin to forge the bonds of a deep and lasting friendship. Intrigued by Na Ri and Yoo Na’s renewed friendship, the innocent, yet steadfast, Im Sun Ji (Do Ah (FANATICS)), and idol-trainee, Seo Mi Rae (Han Chae Kyung), are soon drawn towards the pair. Welcoming the friendship offered by Sun Ji and Mi Rae, the four girls soon become inseparable. With the bonds of true friendship growing stronger every day, the four girls find the courage to face the obstacles of life together.  Based on the popular webtoon, “Odd Girl Out” by Morangg, “The World of My 17” is a high school comedy drama directed by Choi Sun Mi.