sentences:  His holdings in Kokudo and Seibu led to his being deemed the "world's richest man" by "Forbes" magazine for four consecutive years from 1987 to 1990, with estimated net worth of $15–20 billion during the height of the Japanese asset bubble.He was arrested on securities fraud charges in March 2005.On December 21, 2005, Seibu Railway was delisted from the Tokyo Stock Exchange.