it's too small 凪のあすから anime

Plot
For a long time, human civilization had lived on the ocean floor, developing a scale-like layer on their skins called Ena which allows them to live underwater. However, there were many humans who wanted to live above the surface and they moved to land creating a fundamental separation between the two. After Nami Junior High School closes down, four 14-year-old students from the sea village Shioshishio Plot have to attend Mihama Junior High School on the surface. What follows is their struggles adjusting to a new environment and the relationships between the land and sea humans, while dealing with their own newfound feelings that have just started appearing with the end of their childhood.
長い間、人類文明は海底に住み、皮膚に鱗状の層「エナ」を発達させ、水中で生活してきた。しかし、地上での生活を望む人類も多く、彼らは陸上に進出し、両者の間に根本的な隔たりができてしまった。奈美中学校が廃校になり、海の村・汐汐から4人の14歳の生徒が海上の美浜中学校に通うことになる。新しい環境、陸と海の人間関係、そして幼少期が終わったことで芽生えた自分たちの気持ちと向き合いながら、彼らは奮闘する。

凪のあすから A Lull in the Sea anime