Unexploded Bomb ·不発弾

A press conference is held by a large electrical manufacturer. The press conference discusses improper accounting by the company of 150 billion yen. Finance Consultant Ryo Koga manipulates the CEO of the electrical manufacturer. Yumiko Kobori of investigation unit 2 suspects fraud and feels it's not right that the company was able to avoid delisting on the stock market exchange. At that time, the head of the management audit department commits suicide. Shortly afterwards, Ryo Koga secretly meets with Shozo Higashida. Yumiko Kobori doubts whether the man committed suicide. Who is Ryo Koga ?