Nanjo Aki is a female investigator at the Tokyo Central Investigative Headquarters of an international secret investigation agency with its headquarters in Paris. Following orders from the Paris headquarters, she secretly investigates major international conspiracies and criminal cases, and is an enforcer of justice who strikes down the roots of these crimes before evil organizations can carry them out. She has two excellent subordinates, and under them is another subordinate who is like a female leopard, and they solve the cases. As soon as she receives orders, Nanjo Aki gathers her subordinates at a secret hideout, draws up a meticulous plan, and executes it.