Im Shima Kawauchi I was taken in by my kind grandfather following the divorce of my unloving parents. My grandfather passed away in due time, leaving me all alone. Consumed by grief, I cry by the oceanside at night when an accident causes me to fall into the water. Unable to swim, I'd nearly drowned but I was saved by an incredibly handsome merman. Seeing my emotional state, the merman—who I've named Isaki—insists that I'd take him home until I'm fully recovers.