Rintarou Kawana

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.

65 million years ago, the knights of the Ryusoul Tribe were selected to participate in a war campaign against the dictating Druidon Tribe who sought to rule Earth. But the Druidon's war campaign was halted by the meteor that brought the age of the dinosaurs to an end, forcing them to flee into space. Meanwhile, the Kishiryu were placed in a deep sleep as a failsafe should the Druidon return. The chosen knights choose to live in peace while passing their mantle down across generations. In the present day, the Druidon return to reclaim Earth as the current generation of knights, the Ryusoulgers, battle them with the support of Ui Tatsui and her father Naohisa Tatsui.

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!

The OhgerCrown, the proof of kingship owned by Gira Husty, has been stolen by the Tylerian Donking, a member of the Alienizer gang, and his servant Ihab. Gira and Prince join a battle fight to retrieve the OhgerCrown, the prize for winning the battle fight. Prince wins steadily, but when he meets a boy who is determined not to lose in order to save his sister, he senses something is wrong.