On a mission to a distant planet, the crew of the E.X. Celsior found themselves at the forefront of humanity, exploring life in a different solar system thousands of light-years away. Their mission is to explore the planet LEV-1T-AN-623, a candidate for colonization by humanity, but also the first planet observed with potential signs of existing life. Upon reaching their destination, the crew finds that the life in this solar system is of a scale beyond anything they could imagine. However, as they prepare to learn more, the ship suffers a fatal collision with an unknown object that sends them hurtling to the surface of the water world. The sole survivor of the impact, Corporal Lio Bitz, records his fight for survival as he comes face-to-face with the unique life of the planet he calls Leviathan 623.