Yeohui has been enjoying a satisfactory sexual relationship with Seunghyun. But when she comes across an adult video of a girl and two guys having a threesome, her interest is piqued. Wouldn’t two guys be better than one? Seunghyun agrees to the idea but under one condition — that she finds the second guy herself. As Yeohui sets off to look for the perfect new addition to their bedroom fun, she fails to find anyone that suits her tastes… But one day, a nerdy-looking guy with messy hair approaches her and hands her a letter. Who exactly is this strange person? And just when she was about to ignore him, something catches her eye… Wait, aren’t his hands really big? And his body… doesn’t it look nice and fit? “I found him. The perfect second guy for my threesome.”