Shiina Natsukawa

Honoka Takamiya was perfectly happy with his completely average and normal life. His primary problem in life was the fact that he shared a school with the school's "Princess," Ayaka Kagari. Both girls and boys fawn over her which makes Honoka's life difficult since he rides the same bus as her in the morning and sits next to her in class. What's worse is that if he even idly interacts with her her fan club takes him out back and beats him up! (myanimelist.net)

15 year old girl Misaki Akeno aspire to become a Blue Mermaid, a group of women trained to operate navy warships for the purpose of international peace and handling maritime disaster. She.

This story begins in the age where 'demi-humans' which is humans with some sort of special power have been accepted into mondern civilication. Tetsuo Takahashi who is a biology teacher wants to study demi-humans and his luck smiles at him and ends up in the same school as 4 of these demi-humans. The story follows as he trys to 'interview' these demi-humans and learn more about them but with alot of failure on his end and comedy at its finest on the other end. (imdb)

A party of adventurers attempt to defeat a demon lord. They fail, accidentally sending her back in time. The demon lord decides to go to the adventurer school where these four girls trained, and become their teacher, all in the hopes of getting them expelled.

The first place Nonoka Komiya ever called home as a child was Lake Kiriya City, and she's headed back. Sometime in the last seven years a mysterious saucer appeared hovering over the town, changing everything. (imdb)

Living by the sea, protecting the sea, and journeying across the sea…They’re the BLUE MERMAIDS! Because of a shift in tectonic plates around 100 years ago, Japan lost much of its area to submergence. To preserve Japan’s territories, Coastal Cities sprung up, one after the other. Eventually, they became Marine Cities, and along with the expansion of sea-lanes to connect them, the need arose for a sizable staff to protect the seas.