Hae-beom owns and runs his own restaurant. While his food is top-notch, his service skills leave much to be desired, but not for a lack of trying. Unfortunately, Hae-beom has a terrifying visage, appearing closer to a mobster than a chef. This scares off most of his clientele, except for a select few drunkards and those brave enough to keep coming back. It's on another slow evening when a boisterous group comes in. They get just drunk enough not to be afraid of Hae-beom but also end up being complete asshats. Though Hae-beom appears rough and tumble, he's deep down anything but, and though he tries to calm the wild group, things quickly turn into something violent. Thankfully, before Hae-beom has to take a hit, a regular customer jumps in. Hae-beom's savior turns out to be Baek Sang-ah, a merman performer at an aquarium. After seeing Sang-ah perform, Hae-beom is smitten and desperately wants to grow closer to him. He gets that very opportunity when Sang-ah asks Hae-beom to be his kissing partner, as merpeople have to consume human fluids in order to turn their tail into human legs. This is a deal that benefits both parties: Sang-ah gets his legs, and Hae-beom gets to have a physical relationship with his crush. But as time goes on, feelings and desires begin to change. Fear and uncertainty start to cause tension in this pleasant arrangement, and it isn't long before everything falls apart.

BL Library