After I-Han Jeong’s mother and brother died in a car crash when she was just 9 years old, she was raised by Chi-O Han and his parents, who lived next door. Now about to attend university, I-Han suddenly finds herself living with Chi-O under one roof, and she realizes that she feels more than just familial affection for her brother figure. While trying to deal with her trauma and the awkwardness of freshman life, I-Han meets Yu-Jin Seo, a champion judoka at their university who is the spitting image of her late brother. And now he's moving in next door?!