Haga, Nicola, and Amano sneak into Vale Castle, the stronghold of the Asobing debuggers. Haga's goal is to steal the debug stone of a malicious debugger and neutralize him. And Amano wants revenge for the death of Ruu... But the game's main quest is triggered, and the three are captured and locked in the castle's prison. They try to escape, but the debugger Sakai is walking towards the prison.
