Shirogane no Soleil: Contract to the Future: Mirai e no Keiyaku

In the Northern Europe lies a ruin called "The Ship of Time". Inside is imprisoned a dangerous specie called Berserk. But one day, the Berserk solves the riddle of the seal that has kept it imprisoned for so long and breaks free. Aimed to set the world ablaze once again, Berserk is about to confront the girl with the silver wings, a battle maiden Valkyrie. You play a young man, oblivious to the fact that some things from Norse mythology are not just myths, enjoying his school life until one day, you meet the battle maiden Sol Valkyrie and your whole world changes.