The Japanese "AT Mech" regiment is rarely seen in Axis and Allies online play, and is usually deployed by newer players that are unaware of it's disadvantages. So take a moment to learn why you shouldn't be making them, and hopefully we won't have to have this discussion again...
Halftracks - As can be seen in the real-life photo on the left, the Type 1 Ho-Ki halftrack was not the most nimble armored halftrack of WW2, and looked more as though it should have a crane mounted on it, rather than weaponry. In the halftrack unit comparison you can see that the Japanese halftracks have the lowest defense value of 2.
Tank Destroyers - Then there is the Japanese Type 1 Ho-Ni tank destroyer, which in reality is little more than an AT gun with tracks on it. Very poor crew protection as can be seen on the right. In the tank destroyer unit comparison you can see that the Japanese Type 1 Ho-Ni comes in dead last in every catagory.
Upgrades - When it comes to upgrades, Japan is basically an infantry country with good Arties. In looking at the Japanese Upgrades you will notice they are missing the mechanical reliability and gyrostabilized tank gun upgrades which are of great benefit to other countries, meaning the Japanese AT Mech will be further outclassed once their opponents have upgraded. The "Mech" stage of the game is probably Japan's greatest challenge, it up to you to find a way to survive this portion of the game, without making AT Mech.