Ryuichi Koike, a "sokaiya" corporate racketeer on trial for extortion, demanded payoffs during direct meetings with executives of firms involved in the huge financial scandal surrounding him, prosecutors said Monday during his Tokyo District Court trial.Describing Koike, 54, as a "skillful" and "aggressive" sokaiya, prosecutors in their opening statement detailed his close, dubious ties with the nation's four biggest brokerages and Dai-Ichi Kangyo Bank. Sokaiya purchase shares in companies to gain access to shareholder meetings, then solicit payoffs by threatening to disrupt the meetings by making embarrassing revelations.The four brokerages -- Nomura Securities Co., Daiwa Securities Co., Nikko Securities Co. and the collapsed Yamaichi Securities Co. -- and Dai-Ichi Kangyo accepted Koike's demand of payoffs, fearing his influence as a powerful sokaiya who had sent piles of questionnaires to companies based on very detailed information he had collected before the annual shareholders' meetings, prosecutors alleged.Prosecutors said Koike also demanded the payoffs through direct meetings with Hideo Sakamaki, former Nomura president. In his first hearing held in December, Koike pleaded guilty to taking about 12.4 billion yen in illicit payoffs from the four securities houses and Dai-Ichi Kangyo Bank.He admitted accepting 370 million yen from Nomura, 202 million yen from Daiwa, 14 million yen from Nikko, 11.7 billion yen from Dai-Ichi Kangyo and 107 million yen from Yamaichi. Koike is charged with violating the Commercial Code by accepting the payoffs and the compensation from the four brokerages for trading losses.His ties with the four brokerages were strengthened in the late 1980s when he acquired 300,000 shares in the securities firms using loans from Dai-Ichi Kangyo Bank, prosecutors said. Koike had built up close connections with the bank since around 1983, when he started acting as an influential sokaiya at the bank's shareholders' meetings.He started opening accounts at each securities under the names of companies owned by his relatives and began trading securities in the following years. But he had suffered a large amount of trading losses. As of January 1994, for instance, he incurred losses of 340 million yen, mainly due to the fall in value of his East Japan Railway Co. stock, which he purchased through Daiwa when it was first listed in October 1993.He strongly demanded that the securities company compensate him for the losses, prosecutors said. Koike also requested that Daiwa conduct discretionary trading for him with loans from Daiwa Finance, a nonbank affiliated with Daiwa Securities Co., to make up for the losses, prosecutors alleged.The Securities and Exchange Law bans brokerages from compensating clients for investment losses and from conducting discretionary stock deals on behalf of investors.Daiwa, like its former Big Four counterparts, transferred profits made through stock transactions on its own account to Koike to make it appear as though he placed the original orders, prosecutors alleged.But his trading losses snowballed at his other accounts, such as at Nomura and Nikko, by June 1994, according to prosecutors. Koike then approached Yamaichi in June 1994, demanding it conduct discretionary trading for him with loans from DKB.Dai-Ichi Kangyo made a total of 20.7 billion yen in loans to Koike through Daiwa Shinyo, a nonbank affiliate of DKB, on 86 separate occasions from May 1993 through September 1996 in order to buy his silence during its shareholders' meetings, prosecutors said. Of the total, the charges include just 11.7 billion yen in payoffs made on 52 occasions because the statute of limitations on some funds has already expired.