Rental Magica - Season 1 Episode 15 Legend of the Mermaid

Shinogi and Moroha Minagi request that the Astral members return a funadama they found to a shrine on a beach. When Itsuki and Kuroha attempt to return it, they are sucked into the past due to the magical pollution in the area. They meet a fisherman, Hyōdō, who explains that he has been attempting to find a mermaid due to the miraculous healing abilities their flesh gives when it is consumed. In the present, Honami, Adilisia, Mikan, and Nekoyashiki are told the legend of the mermaids from an old woman, who recounts that mermaids return to eat those that consumed them. Itsuki and Kuroha are subsequently attacked, and Kuroha manages to call upon the spirit of Hyōdō's wife, which materializes in a funadama, causing the mermaids to chase after it instead, and Itsuki and Kuroha return to their own time. Later, Shinogi recounts that the shrine is being worshipped again, and Itsuki realizes it is likely one of Hyōdō's descendants.