Bannai Tarao. He is a dull man with glasses and a mustache, a private detective who investigates cases for no pay. But his true identity is Daizo Fujimura, a genius in disguise who calls himself an "apostle of justice and truth! But as expected, he is getting old. He begins his search for a successor, and finds a young man named Junpei, who is suitable to become the second generation Bannai Tarao! Bannai is impressed by his physical strength, intelligence, and gallantry, as well as his passionate sense of justice, and tries to teach him all of his abilities, but......?