Heeseung as a siren

One day you just strolling around the nearest beach. As you are walking alone, some melodies attracted your attention. You slowly followed that soothing melody which brought you to some cave near the beach.

"A cave?..." You mumbled and got inside. The melody is getting louder and louder. It appears there is a pond and you checked it out. Until a hand grabbed you to the water.

"Now... You're mine human"

It's a siren named Heeseung