A huge creature has suddenly appeared in Tokyo Bay. Behind its appearance is the Shiromori Shuu, a secret society that has been controlling Japan from the shadows using occult powers.
However, at that time, there existed in Japan an organization to preserve the peace called ASY. The monster is completely unaffected by ASY’s fierce attacks. Just when they thought it was all over, a large shadow flew onto the scene. ASY had a trump card. Its name: Ginko. With overwhelming power, Ginko drove the monster into the open ocean and finally annihilated it. The plan a success, a bright light flew to Ginko’s chest and a strange scene appeared before the pilot’s eyes. The figure of a girl floating in midair, wrapped in light...
The girl who suddenly appeared was "Rouran". She doesn’t know who she is or where she came from. She also doesn’t know why it is that when she senses gousen [golem?] or kyoushi [reanimated corpse] she goes into combat mode and transforms into a being seeking to destroy. As Rouran worries about these aspects of herself, Tetsuya, who lives in Tokyo Tougenkyou, kindly watches over her.
Yamato is a member of ASY and pilot of Ginko. He is the first to have made contact with Rouran while she was in combat mode. With a strong sense of justice, he regrets involving civilians when he fights. Mahoro, also a member of ASY, adores her older brother Yamato to an unusual degree.
Who on earth is this Rouran person? How will this story develop? Find the answers in Kikou Sennyo Rouran!!