Slayers (2003)

Lina and Gourry visited the town in a certain beach. In that town, a mysterious incident which is that the person who had eaten the octopus was not able to speak the languages other than the octopus language happened frequently. And, Gourry who does not know the incident eats slices of raw octopus, and he cannot speak words other than the octopus language. Ameria and Zelgadiss who came there by chance are involved in the trouble, too and the fight with the clan of the octopus which lives in the beach starts.