Following the death of his wife from a plane crash, tax inspector Haruma is convinced that the tragedy was a premeditated crime. A number of clues connect him to a tax evader Murakumo, who is about to perform an evasion scheme of US$ 7 billion.

Shinko (Ryoko Shinohara) is an accounting auditor who chases after tax evaders and embezzlers that hard working citizens needlessly pay for. Shinko has a knack for solving cases without common sense or standards.