Japanese software sales were down 21.1 per cent compared to last year, while hardware fell 0.9 per cent, according to Famistu publisher, market analyst and MCV media partner Enterbrain.
The decline is blamed on the delay of Super Smash Bros. Brawl on Wii, which fell outside the data collection preiod for January's sales report.
Nintendo's Wii platform enjoyed another strong showing in January, posting a 20 percent year-over-year growth in hardware sales to 480,000 units, with Nintendo's Wii Fit topping the software chart for the second consecutive month.
Wii Fit has already sold 1,209,000 copies in its first nine weeks of release, not just outperforming Wii Sports (which sold 908,000 in its first nine weeks), but also recording the fastest-ever sales pace for a Wii game. Wii titles also occupied the half of the top ten slots of January's software chart.
The DS Lite continued to outsell all other gaming systems with 579,000 units sold. The PSP hardware unit sales leapt 70 per cent over 2007, to 400,000, while the PS3 registered a year-over-year growth of 10 percent, to 166,000.