MikuMikuDroid needs an original MikuMikuDance distribution for execution. At first, let's visit http://www.geocities.jp/higuchuu4/index_e.htm and get MikuMikuDance (Multi Model Edition). After that, unzip it under the SD card area(/sdcard/MikuMikuDroid) on your Android phone. Note that you must get some motion files (.vmd), but most of their distribution site information are written in Japanese.
Here is a little more information for installation. http://sourceforge.jp/projects/mikumikudroid/howto/install
When I open this app on my phone, a notification is appeared. The title is 'Setup alert' and is says 'Pleas put toon??.bmp files in MikuMikuDance Ver5.x on /sdcard/ MikuMikuDroid/Data/'. I would be very pleasant if you can help with this problem.