 The Hennessy Japan Fund Trades, Portfolio, part of California-based Hennessy Advisors Inc. NASDAQ:HNNA, disclosed this week that its top buys for the fiscal fourth quarter included a position boost in Olympus Corp. TSE:7733 and new positions in Z Holdings Corp. TSE:4689, Mercari Inc. TSE:4385 and Murata Manufacturing Co. Ltd. TSE:6981. 