TOKYO, Feb 20 - Japanese stocks edged lower by the close on Friday, with Shinsei Bank <8303.T> tumbling on profit-taking a day after its strong market debut and chip-related issues weakening on disappointing U.S. data. But some blue chip exporters like Japan's third largest auto maker Nissan Motor Co <7201.T> drove higher on a weaker yen, although most later pared gains made in morning trade. After spending much of the morning tiptoeing in and out of positive territory, the Nikkei benchmark average <.N225> slid in the afternoon to end down 0.31 percent or 33.11 points at 10,720.69. That followed a 0.72 percent rise in the previous session.//