Warlord Games has expanded their Build An Army and Get a Free Tank deal to the Japanese faction for Bolt Action. It's pretty simple, just click on their Build An Army program (formerly their Army Builder program, but, y'know, copyrights and all) and create yourself a force. Boom! Free tank!
The Japanese add to the British, US, Soviet, and German forces who were the initial factions available to get this special deal. Using just a few drop-down menus, you can quickly and easily create a force and then just pick what sort of free tank kit you want. It's not at random, either, you get to pick the kit you want for free. For the Japanese, there's a choice of four.
It's a pretty simple way to get into Bolt Action and you get a nice perk for it as well.