Bit Racer (Dexturbo)  is actually a pager motor racer. And it needs the charger to charge up the micro NiCd inside the racer.  My Japanese is getting rusty, I think the manual mentions that 30 sec charge will let the racer runs for 3 min. So here it is, the Japanese manual and it is the only manual inside the box !!

For USD 12.82, it is a very good deal. And wait until I have time to convert it to solar-power, and I think it is pretty BEAMable to me : -)