Nintendo strengthened its hardware sales lead in Japan in May, with the Wii and DS once again outselling the PS3, PSP and Microsoft Xbox 360.

The latest hardware figures show that the Wii is outselling the PS3 five-to-one in Japan, with 251,794 Wiis finding their way into Japanese homes. This is a larger gap than last month, when the Wii outsold the PS3 by four-to-one.

Meanwhile, Nintendo sold 620,670 DSs compared to Sony's 123,673 PSPs, replicating its five-to-one lead in console sales.

The 360 trailed right at the back, with 11,082 units sold.

Nintendo, obviously, is likely to be pretty chuffed. Especially since George Harrison, senior vice president of marketing and corporate communications, recently said that Nintendo expects to take a 40-50% share of the home console market over this generation.

Overall, Japanese hardware sales declined over the course of the month. The back end of May saw, for example, the DS dropping by around 50,000 sales from the week ending May 11th to the week ending May 18th.