0326 GMT - The dollar is expected to trade between 154.30 and 157.60 yen this week as investors seek clues on U.S. and Japanese monetary policy, says Sony Financial Group analyst Kumiko Ishikawa. Market participants are eyeing potential back-to-back Bank of Japan interest-rate increases in September and October, following hawkish remarks from board member Hajime Takata last week, she says. If another board member Kazuyuki Masu takes a similarly aggressive stance in his speech on Thursday, markets could further price in such a scenario, driving the yen higher, she adds. The dollar was last trading at 156.10 yen.