Even though he should be able to die like a normal human, Kiyonosuke has been living for thousands of years, all because he accidentally "married" a merman. But Kiyonosuke can't give up on his humanity and has been looking for a cure to immortality. (Source: MU)
Amano works in a hotel that caters to visitors from the other realm. When Tsukiyomi, the king of the other realm visits the hotel, Amano discovers the truth behind the disappearance of his childhood friend, Mitsuki.