The Nikkei average fell for the second day in a row on Tuesday, losing 1.43 percent as exporters such as Toyota Motor Corp declined on concerns about a slowdown in the key US market.
Comments from Bank of Japan Governor Toshihiko Fukui late in the session suggesting the central bank remained on course to raise interest rates as early as next month accelerated selling.
"Sentiment was already weak," said Hideyuki Suzuki, investment information manager at SBI Securities, referring to concerns about a slowdown in the US economy, higher interest rates and a decline in US stocks. "Then the comments from the BoJ governor raised concerns that we may see a rate increase earlier than many people had expected."
The Nikkei finished the day down 211.94 points at 14,648.41 after falling 0.13 percent on Monday. The TOPIX index was down 1.14 percent at 1,510.32.
Fukui said policy decisions should be taken early if warranted by economic conditions, rekindling speculation the central bank would soon raise interest rates from zero.
Fukui has been under fire for his 10 million yen ($87,000) investment in a fund set up by former fund manager Yoshiaki Murakami, who has been arrested on suspicion of insider trading.
Toyota, the world's most profitable auto maker, fell 1 percent to 5,780 yen. Electronic components maker TDK Corp declined 2.5 percent to 8,430 yen. Oil explorer INPEX dropped 3.1 percent to 890,000 yen after US crude oil futures ended sharply lower in New York trade on Monday.
After recent declines, Japanese stocks look overvalued, especially if investors take into account the likelihood of upward earnings revisions, said Jun Morita, fund manager at Chibagin Asset Management.
Shares of Web advertiser Adways Co Ltd, which made its debut on the Mothers market for start-ups, finished the day flooded with buy orders after a brokerage made an errant order. Adways ended the day with a glut of buy orders at 1.67 million yen, up more than 19 percent from its IPO price of 1.40 million yen.
Brokerage Tachibana Securities said it placed a mistaken sell order just after trading opened. It offered 2,600 shares at 1,670 yen each - a small fraction of Adways' debut price. Investors then scrambled to pick up the erroneously offered shares on expectations Tachibana would have to buy them back.
Japan's REIT index fell 4 percent, extending losses from the previous day, when the index lost 2.92 percent after the Securities and Exchange Surveillance Commission called for disciplinary action against Orix Corp's asset management firm and its REIT, Orix JREIT Inc.
This second call for a penalty against the REIT industry since the first one in April has stoked concerns about compliance, hurting all REITs but one listed on the Tokyo Stock Exchange. Orix JREIT sank 7.4 percent to 652,000 yen, becoming one of the worst performers on the TSE's first section. Overall trade was thin, with 1.47 billion shares changing hands on the Tokyo exchange's first section, compared with last week's daily average of 1.99 billion. Decliners outpaced gainers 1,260 to 336.