[citation needed] When the Maiden of Life, Ruri Sarasa, and her bodyguard, Gravity User Chelsea Rorec escape to the surface, they take refuge with swordsman Rumina Asagi and his bespectacled best friend Ginnosuke Isuzu.
Realizing Ruri is in danger, Rumina vows to protect her, even if it means going to the Underground to rescue her from her eventual captors before she gets sacrificed.
Their hatred for the surface world stems from the belief that they were abandoned by them, which really isn't true since only the scientists actually knew of their existence underground.
The Ron lie dormant, but the Company intends to use Ruri's power of life to revive them and set them upon the surface world to punish those who had wronged them so many years ago.
When they are finally seen, it is revealed that in their dormant state the Ron resemble dolphins, and only become the dragon-like life forms through the Maiden's power.