But Takei's reputation was tarnished in 2004 by his conviction on charges of ordering the wiretapping of a journalist who had written articles criticizing his company.
Takei turned to illegal snooping after the critical articles triggered a decline in his company's share price, making him suspect someone was working behind the scenes to discredit the company, the Tokyo District Court ruled.
Takei was sentenced to three years in prison, suspended for four years, and his company, one of Japan's biggest consumer loan corporations, was fined 1 million yen ($8,700).
Takei was listed as Japan's richest man, along with his family, in the 2006 Forbes magazine listing of the world's billionaires, with assets of $5.4 billion.
But Takei's reputation was tarnished in 2004 by his conviction on charges of ordering the wiretapping of a journalist who had written articles criticizing his company.
Takei was sentenced to three years in prison, suspended for four years, and his company, one of Japan's biggest consumer loan corporations, was fined one million yen, or about $8,600.