Due to the tragedy of the giant monster attack in the future, causing brother and sister to be separated. Errol Nathaniel thought his brother was dead, determined to become a fighter robot pilot to fight a monster named Gollum.

Together with his loyal friends from the Flamingo division, Errol travels the world in order to destroy all of Gollum. Until his meeting with El Diablo, the leader of the Helium group, changed his life goals.

Errol tries to uncover who El Diablo is and ends in an unexpected secret. Raindrops that reveal everything.