High School Fleet, a TV anime series which released in 2016, will be getting mobile game coming in 2018 Spring, although its developer is still unknown at this point. In any case, a teaser site has gone live.
The game will be supervised by the Suzuki Takaaki, the series creator. Unnamed still, the game will revolve around ship battles, a given considering the theme. No other details have been disclosed yet.
So a little backstory, in case you have never heard of High School Fleet. A large portion Japan has sunk into the ocean a century following the Russo–Japanese War, which has forced the population to live on water. Protagonist Misaki Akeno of the Yokosuka Girls’ Marine High School is studying to be a Blue Mermaid, a special task force that safeguards the marine world. She is made the captain of the destroyer ship Harekaze. Leading her crew of classmates, she sets off on a dangerous journey.