On the day of a full moon, Kyle and Dahlia decide to take a camping trip to Mako Island, as a goodbye to summer. But, they accidentally land in the moon pool of the island which changes their lives forever. The force of the moon turned Kyle into a merman, and Dahlia into a mermaid. Anytime they touch water, they grow a tail. The brother and sister, must stick together to get used to the recent developments that have hit them.