TOKYO, April 21 (Reuters) - Japan's Nikkei share average slipped on Friday, easing away from an eight-month peak it touched earlier in the session as investors refrained from making active bets ahead of the Bank of Japan's policy meeting next week.

The index closed 0.33% lower at 28,564.37, after rising to 28,778.37, its highest level since Aug. 26. The index is on course for fourth straight month of gains - the last time it went on a similar run was in 2021.

The broader Topix ended the day down 0.20% at 2,035.57, but clocked its second straight week of gains.

"Gains on the Nikkei were capped as investors awaited the outcome of the BOJ's policy meeting," said Yugo Tsuboi, a senior strategist at Daiwa Securities. "But the trend that investors seek to buy undervalued stocks has not changed."

Corporate governance in Japan has suddenly become a hot topic, rousing the stock market out of decades of lethargy, with foreign investors purchasing roughly 1.59 trillion yen worth of Japanese shares last week, their biggest buying in five years.

Paul O'Connor, head of multi-asset at Janus Henderson Investors, said 2023 could be a year when investors value resilience of Japanese companies profit growth.

"This year, Japanese stocks look set to deliver faster earnings growth than equity markets in the eurozone, UK and the United States."

The BOJ is scheduled to hold a two-day meeting next week. Nearly 90% of economists polled by Reuters said the central bank's new chief Kazuo Ueda will not start unwinding its ultra-easy policy at the meeting.

Uniqlo brand owner Fast Retailing Co Ltd was the Nikkei's biggest drag, sliding 1.54%, while technology investor SoftBank Group Corp lost 1.73%.

Precision machine maker Disco Corp surged 14% to become the top gainer on the TSE's prime market after posting a record group annual operating profit.

(Reporting by Junko Fujita; Editing by Sonia Cheema and Sohini Goswami)