The novel is called "My Mermaid Gentleman".
The male protagonist is a mysterious species caught by a research team from the deep sea, a mermaid. Because of his human body with a fish tail, and his intense ferocity and immense strength, with a lifespan that can reach up to 350 years, humans want to discover the secret of the mermaid's longevity and its unique human-fish body structure. After capturing the mermaid clan with great effort, they immediately sent them to the National Secret Biological Research Institute.
The female protagonist is an intern researcher at the institute, working and learning under the director of the institute.
Upon first seeing the mermaid, the female protagonist was captivated by the mermaid's beauty and mystery. Over time, she gradually fell in love with this creature, known as the Deep Sea Elf, and secretly took care of the mermaid during subsequent research.
