Jaekyung and seerim have been enemies from high school, they were best friends since they're 4 years old. seerim mom and Jaekyung mom are best friends, but it's not happening to Jaekyung and seerim, they keep fighting even though they're living together. Jaekyung Joo is known as a great MMA athlete in college, everyone knows him for his bravery and his confidence. but all seerim knows is Jaekyung still a spoiled little boy who's stubborn and short tempered.