The latest installment of Square Enix's hit Kingdom Hearts franchise debuted in Japan last week and initial sales figures are strong.

It was the best selling game in Japan with 213,579 copies sold, although that's less than previous games in the series.

In 2010, Kingdom Hearts: Birth by Sleep (PSP) shifted just under half a million units in its first week of sales while 2009's Kingdom Hearts: 358/2 Days (DS) sold 295,205 during its debut week.

Early cycle

Part of the reason likely lies in the timing of the game's release.

When Square Enix released 358/2 Days, the DS had been on the market for well over five years and the DS Lite was already two years into its lifecycle.

Equally, Square Enix released Birth by Sleep almost six years after the release of the original PSP. Dream Drop Distance, by comparison, launched just one month after the first anniversary of the 3DS.

None of this is to suggest the 3DS is an unpopular system, only a new one. Last week, it sold 121,921 units in Japan, outselling the PS3 (23,771), PSP (18,356), and PS Vita (12,105) combined.

Indeed, it accounted for a staggering 65 percent of all hardware consoles sold during the week, which is a figure few would have anticipated after last year's rocky launch.

[source: Gamasutra]