Before eradicating humankind from the world, the gods give them one last chance to prove themselves worthy of survival. Let the Ragnarok battles begin.
Teenage math whiz Kenji Koiso agrees to take a summer job at the Nagano hometown of his crush, Natsuki. When he arrives, he finds that her family have reunited to celebrate the 90th birthday of their matriarch. His job: pretend to be Natsuki's fiancé. Meanwhile, his attempt to solve a mathematical equation causes a parallel world's collision with Earth.
The story follows a team of pirate mercenaries known as the Lagoon Company, that smuggles goods in and around the seas of Southeast Asia in the early to mid 1990s. Their base of operations is located in the fictional harbor city of Roanapur in southeast Thailand near the border of Cambodia.
