Legacy-X : The Scarlet Moon (Book 1)

Raiken, a fifteen-year-old knight in training, stumbles upon a young android girl that fell from the sky. With a lost memory and nowhere to go, he takes her in. But after doing so, it doesn't take long until a series of events take place within the city and his academy. Later he learns about an ancient artifact left from the last great war, the scarlet stone; a dangerous stone that has mysterious powers. Knowing about the immense power it does hold, Necrohl, an enforcer of the planet Jhra descends into Ira to put his plans into action. With the city's future hanging on the balance, it is up to Raiken and his friends to save not only themselves but maybe even the whole planet.