About

A long, long time has passed since humanity vanished. Civilization collapsed due to nuclear testing, and the planet "No_1852185" has transformed into a vast ocean as far as the eye can see. In this world, coral grows thick over sunken cities, and giant creatures swim freely. At the apex of this sea reign the "Mikado"—aquatic hazardous lifeforms of overwhelming power. One of them, the cynical Colosso, often says, "I don't want to get involved in anything troublesome." ...However, triggered by a mysterious encounter and a journey with companions, he finds himself dragged into one major incident after another occurring across the ocean!