Seto no Hanayome Temporada 1 Episódio 18

The whole class went for a sudden trip to Kyoto. After an incident where Maki attacked Akeno, Sun apologizes to her, but Akeno issues that shes interested in Suns mermaid body and asks her permission to investigate them at bathroom. Unknown to them, Nagasumi and Mawari misheard this conversation and issue an investigation of their own.