Livedoor Co. Chief Financial Officer Ryoji Miyauchi, who prosecutors arrested Monday, was central to the company's rapid expansion since joining its predecessor, Livin' on the Edge, as a director in July 1999.
Miyauchi, 38, was the financial brain behind Livedoor President Takafumi Horie, leading the firm's merger and acquisition strategies.
Miyauchi graduated from a commercial high school in Yokohama in 1986 and became a certified tax accountant in December 1995.
In 2000, he suggested that Livin' on the Edge, originally started as a Web site design company, become a listed company, when it was still one of his clients.
Last March, he became a director of Livedoor Marketing Co., which is at the center of the current investigation.
Last Tuesday, a day after prosecutors raided Livedoor's head office, Miyauchi returned from a business trip to China and said, "I think my actions led to (the raid)."