The big kingdom of Aquatica

Note:The 9 girls are not being called TWICE and also the 9 boys are not called EXO in this story. All of the characters in this story are merpeople.
Couples:Suho and Jihyo, Jeongyeon and Baekhyun, Nayeon and Xiumin,
Mina and Kai, Lay and Momo, Dahyun and Sehun, Chanyeol and Chaeyoung,
Chen and Tzuyu ( I know that Chen is married and have daughters), and Sana and Kyungsoo.