Where have you gotten that number? I see Japanese Average height is 5'7" while American Average height 5'9" to 5'10" depending on the state. Finally, there's loads of Japanese exchange students at my university, my roommate among one of them, and I'm a good deal taller than all of them. Not only are they short, but they're really skinny too, which aids in the "tiny" bit.
I felt like raiding my neighbor's fridge but now after reading this I'm reconsidering as she might claim she was a non-combatant neighbor who had no idea the attack was going to come, and she might nuke my fridge in retaliation