In a world of black and white, ore dug from the cave is shedding colored light. Mikuro, identifying himself as the 'Black Fox' bandit appears in front of the white-haired boy Kohaku who is captured in the back of a cave by gang of thieves. Mikuro who collects the ore shedding 'colored' light, says proudly that he has a 'dream' to fulfill in this world of black and white. 'It's decided! From now on you will be my little brother.' Kohaku had lost hope for life after his parents were murdered, but he is forced to be Mikuro's little brother and together they start running towards the world out of the cave.