There is no one in the world Choi Euncheol loves more than his dog Jong-gu. Having been there for him through heartbreak and happiness alike, the pup is as loyal as can be. The two are best friends, and more alike than they look…because Euncheol loves a little bark and bite in the bedroom. But when Jong-gu mistakes a little nighttime pet play for an attack on his masochistic master, he valiantly rushes to his defense and bites the "assailant" square on the buttocks! Euncheol decides to end things with his lover, and is now left with no one but his precious pet to help him grieve his relationship. When he awakes the next morning, however, Jong-gu has gone missing! In his place is a cute guy who seems strangely familiar, but Euncheol can’t quite put his paw -er, finger- on why…