Tokyo stocks fell sharply Monday, with the key Nikkei index closing below the 10,000 line for the first time since Dec. 10, as exporters were badly hit by a stronger yen relative to the U.S. dollar and euro.

The 225-issue Nikkei Stock Average fell 105.27 points, or 1.05 percent, from Friday to 9,951.82. The last time the Nikkei ended below the 10,000 threshold was Dec. 10 when it fell to 9,862.82.

The Tokyo market was also dragged down by sluggish investor sentiment due to concerns about debt woes in Europe, brokers said.