Two years ago, Jin Kamishina survives a shuttle accident which killed the rest of his family. Now eighteen years of age, Jin lives a solitary existence, often avoiding questions about the rumors of the shuttle pilot (who was his dad) error. Meanwhile, Earth faces possible destruction from an asteroid, so the ISDA works on the “D-Project”. In a facility, Kazuki Tachibana, Jin’s old friend, is being tested for his compatibility with a dragon, which is a success. Elsewhere, Jin witnesses a strange creature kill a woman. The creature then goes after him too, and eventually catches up to him, causing Jin to fall out the window. However, Jin is caught by a mysterious girl who is able to fight off the monster. When Jin wakes up, the girl introduces herself as Toa.