There is an ancient prophecy shared amongst the kingdoms of Chikyu- 2,000 years after their fall, the Territorial Empire Bugnarok will once again rise up to kill all humans. However, five kings and their guardian deity, King-Ohger, will stand up to face them. This is the story of kings who will defend Chikyu, as well as a coming-of-age story for one young man who will achieve kingship henceforth.

Daigo Kiryu and Utsusemimaru set out on a journey in pursuit of Uchu King Dagded who invaded Earth. However, during the battle with Dagded, Utsusemimaru is sent to Earth in another time. They arrived on Earth, which has been invaded by the Deboth Army, unable to save the universe from Dagded. In order to stop the ruined future, they head back to the original timeline, but due to the changes in the timeline, Uchu King Gira reigns over Chikyuu!

In 1958, as a deadly typhoon approaches, a young boy embarks on a perilous journey to a haunted mountain pool, determined to calm a sorrowful spirit whose grief has cursed the village with devastating floods.