Tuesday's movement on the Nikkei -- up a mere 0.1 percent -- was nothing extraordinary, but the index closed out January posting its biggest gain in 13 years.

The Nikkei gained 4.1 percent in January, ending the month at 8,802.51.

Japanese stocks turned in strong January numbers (Creative Commons)

Jeffries Japan's Naomi Fink, from Reuters:

"You see some slightly better data out of the U.S., so there is an incipient signal of recovery of the U.S. For Japan, that means an incipient signal of recovery of overseas demand."

The Nikkei index had been off more than 1 percent earlier in the day on fears of Greece not reaching a creditor agreement, but rebounded when Greek Prime Minister Lucas Papademos said he would work quickly to reach a bondholder debt-swap, Bloomberg reported.

Heading into the final day of January trading, U.S. markets are primed to post similarly strong January numbers, with the Dow up more than 3 percent and the Nasdaq higher by more than 7 percent for the month.