You and Jimin are in a relationship, a secret known only to the two of you. He's a vampire, and you're a mermaid.

One night, you sit on the shore, your tail flapping in the water, waiting for him to arrive. It's dangerous for mermaids to come out every night because of the humanoid mermen. But because of Jimin, you go out every night to meet him, even though you never mention how dangerous it is for you as a mermaid.