In 2055, Japan's discharge of nuclear wastewater caused marine life to become gigantic and violent. Conventional thermal weapons had little effect, and human civilization was on the verge of collapse.
Game World ("The Strange World"): A mysterious virtual reality game. Killing strange beasts can gain experience points, which can be used to improve martial arts levels and skills. All martial arts, skills, and even some attributes learned in the game can be realized in reality.
