1- the farewell?

Luchia, Hanon and Rina believe that everything has returned to calm, but they are wrong. A new enemy appears, with more power and tricks than the previous ones, and with new, more powerful devils. In addition, the appearance of two new girls, Akumi and Kenna, who seem to have something to do with the sea, complicates everything even more. And, as if that were not enough, the return of Taro Mitsuki and other characters. The seven mermaid princesses must unite to defeat the new enemy.

I'm sorry if there are mistakes in the translation. If you find one, please tell me to correct it.