Earth Defence Force Portable takes Japanese No.1

D3Publisher's Earth Defense Force franchise has earned itself another Japanese number one this week, although it does so with just 64,000 unit sales and amidst little competition.

The PSP title is a version of PlayStation 2 game Chikyuu Boueigun 2, which was never released in North America and only in Europe as Global Defence Force. However, it is the best regarded of the series by fans and part of a push by D3Publisher to promote other new entries in the franchise.

Dragon Quest Monsters: Joker 2 Professional on the Nintendo DS sold just 42,000 units at number two in the charts, with third-placed dating simulator Amagami selling just 24,000 units.

The only other new entry in the top ten is manga and anime tie-in Kimi ni Todoke: Tsutaeru Kimochi, which sold 11,000 in its debut at number seven. Number 10 title Phantasy Star Portable 2 Infinity on PSP sold just 9,000 units to secure its place in the top 10.

There is some positive news for the 3DS format though, with one of the three versions of nintendogs + cats returning to the top 10 at number eight. The system is unlikely to see a significant boost though until next week, when Pilotwings Resort is released.