What exactly is a monster? 2020 humans were defeated in a battle and forced out of earth by a species able to transform themselves into humans. Leaving their home, memories, and some of their future weapons behind. These weapons were children they experimented with, using the GreenBlood's (invading aliens) blood and technology. Desperate to take back his home a researcher named Dr. Tenma put some fresh and strange looking green blood into some of the specimens in hopes of strengthening their abilities and hopefully speed up their maturity. But as he was pumping more, the cryogenic pods went into emergency sleep trying to stop the specimen rejecting the blood, and making the specimens sleep for an unknown amount of time. Making them leave with half of their research left on earth. . A massive spaceship landed on earth on the year 2070. Shinichi and his mother witnessed it destroying their neighborhood, and ran inside their home to hide to no avail. Shinichi's mom was seen by the aliens and killed while Shinichi is hidden inside a closet. Later when he finds his mother's corpse, he then swears to avenge her. While finding out the secret of the invaders. .... This is a tragic story of revenge, friendship, and finding out what's the appearance of a true monster.