Monster Girl Doctor S01E02 - The Mermaid of the Waterways

Glenn and Sapphee head to a paradise for water monsters called Merrow Waterways in order to buy some purified water. Sapphee was treating this as a date and enjoying her time alone with Glenn. While on their outing, they meet a mermaid girl named Lulala. Lulala made a living by singing to tourists and she asks if Glenn and Sapphee would buy a song from her. Glenn notices that her gills seem to still be open on land and becomes worried. He then offers to examine her in exchange for her song.