The group learns about Ryugu Palace's hidden past and Otohime's terrifying plan. And they are the only ones who can stop her. Kamenashi suggests they split up into teams and head to Otohime. While breaking up into teams, they are spotted by lookouts and they are thrust in a desperate situation. Meanwhile, Otae, who has been captured by Otohime, is in danger!
Why kelp?! A single leaf of kelp
doesn't have any fighting power!
¿Por qué algas? ¡Una hoja de 
algas no tiene poder de combate!
Por que alga?! E uma folha não
 tem poder de luta nenhum!