In the near future, superhumans called Others, who have awakened to their unique abilities, are active in the world. The world enjoys peace and prosperity thanks to the overwhelming power of the Tiger's Nest, an organization of righteous Others who execute Criminal Others who use their abilities to commit crimes. However, poverty and crime were rampant in the old capital, the slums, which had been abandoned by the Nest. A lone tiger emerges from the darkness of the slums. The rebel hero, Tiger Mask, bares his fangs against Nest's justice. Now a new hero legend begins!