“I never knew a day like this would come where I’d be doing this with you, Sunbae.”

Shim Woojin was Kwon Gyeong’s upperclassman during high school. 

12 years later, they reunite at Woojin’s best friend’s (Inseob’s) wedding, who also turned out to be Gyeong’s first love.

Gyeong, who considered Woojin as his rival in love, and Woojin, who had been fond of Gyeong, find themselves celebrating an after-party by themselves.

As their conversation grows, their night with each other grow too, but…