The Exreme Villainess

Bright and optimistic Korean Japanese teenager Hana lives at a small hot springs inn owned by her mother. When her mother decides to marry a Korean man, she tries her best to reach out to her odd, introverted stepbrother-to-be Yoon Seo, who likes to walk barefoot in the snow. He rebuffs her initial efforts, but her cheer eventually wins him over. With their parents on honeymoon, together Hana and Yoon Seo stand up to Hana's spiteful aunt Yoko and cousin Maya, and the two develop an increasingly close relationship over time. Yoon Seo is forward in his love for Hana, but despite feeling the same way, she is unwilling to break the taboo of a romance between step-siblings. After graduating from high school, she leaves for Tokyo with her admirer Fujiwara Ryu, and loses contact with Yoon Seo. 2 years later, Hana, Yoon Seo, and Maya meet again. Time has led them down very different roads, but the love and the rivalry remain the same.

Hong Seol and Yoo Jung attend the same college, but they couldn't be more different. Hong Seol is a poor, unpopular student with no money, while Yoo Jung is rich, well-liked, extremely smart, and popular. Hong Seol just wants to get through her college career quietly, but finds herself getting caught up in whatever Yoo Jung drags her into. Can Hong Seol break away, or will she continue to be the only person who sees Yoo Jung's true self?

A neurosurgeon with anger management issues becomes the perfect test subject and love interest for an endocrinologist obsessed with the study of hormones.