The benchmark index for the Tokyo Stock Exchange climbed above 30,000 for the first time in a year and 8 months. The gains reflect rising investor confidence amid robust earnings and improving forecasts at Japanese companies.
The Nikkei 225 ended at 30,093 on Wednesday. That's up 0.8 percent from the previous day's close.
Shares of department stores, railway companies and airlines led a rally that was also fueled by expectations for increases in tourists. Semiconductor-related shares were also strong.
The Nikkei has been gaining on increasing demand for stocks by foreign investors. The index has risen more than 4 percent so far this month.
Many expect Japan's economic recovery from the coronavirus pandemic to gain more ground after starting later than in the United States and Europe.
Analysts say Japan's first quarter GDP growth figures released Wednesday also prompted more investors to place buy orders.
But analysts also cited the political impasse over raising the US debt ceiling and a round of bank failures as contributing to anxiety about the global economic outlook.
They also warn that demand from foreign investors may push Japanese stock prices higher than is justified by companies' earnings.