Jeonghoon, a promising executive in the organization, decides to directly teach and discipline the youngest member of the organization. However, Jeonghoon, unlike the rumor, was interested in Hyunjae-who can only look pretty, became close to him. A year later, with those unknown words, Hyunjae disappeared without a trace. “Hyung, I will miss you.” And to make matters worse, Jeonghoon’s organization was attacked and got exterminated. At that time, a familiar face appears from the opposing organization... . “Hyung, it’s been a while. Did you miss me?” The Maknae I love for a year. Return as a "brother" to the opposing organization!