Princess Ayaka, the princess of Inazume, has lived her whole life with a secret: the use of a vision that is forbidden in her country. Ayaka never knew how to use hers until she meets the seadragon princess Lumine, Lumine promise to help Ayaka with her vision if she help her in return. They both agree to keep eachother secrets, but secrets can never keep hidden as the day of her unwanted betrohal, she loses control. Her people where angry and wanting to banishes her out of her kingdom, but her brother, king Ayato, wouldn't accept that. Everything was calm again until one day, a evil sorceror cursed her brother into stone and for her to be forgoten by her kingdom. Ayaka finds herself hopeless until she meets Lumine again who is whiling to help her if she helps her inreturn with another mission. To save herself, her kingdom, she must place trust in a talking fairy, a misunderstood seadragon princess, and a whole underwater kingdom she never know existed. And she must embrace the magic of the vision she's been taught all her life never to use- no matter what it cost.