Gakuen Sensuikan-tai Mermaid Girls

When alien lifeforms known as the Trenchwalkers descend upon Antarctica, they set in motion the transformation of the entire planet. Sea levels surge by seventy meters, swallowing metropolises like Tokyo beneath the waves, while the invaders begin converting Earth's water into a divine substance called Nectar—one that proves fatal to anyone whose body cannot adapt to it. Humanity's hope now rests with a handful of girls uniquely able to withstand the Nectar. Selected to crew submarines and outfitted in special swimsuits, they head for the front lines to take back the planet. Among them is Todoroki Hiro, who, after receiving the dying message of her older sister, sets out in search of Tsunoba Kiriri, the strongest marine soldier alive. Though her heart remains clouded with uncertainty, she resolves to enroll in the Masakado Girls' Academy Submarine Fleet. But her journey is unlikely to be smooth sailing. Armed with water guns and unshakable determination, these swimsuit-clad heroines plunge into high-stakes combat—the ultimate splash-action battle for the fate of Earth begins now!