Usually your allowance is 23kg, check with your airline. Your hotel should have scales to weigh your bags before you leave. If you are pleasant you might get away with being slightly over the limit if you’re traveling with someone who’s under.
When you have fragile unboxed figures, if you think wrapping them in a few t-shirts will protect them, you are dead wrong. They must be absolutely padded from every angle and remember that your case will be flipped, tossed, dropped, and stood on during its journey back home.
Choose your luggage wisely, cheap luggage either has a soft fabric shell, which is only good for clothes, or a plastic brittle shell which will crack as soon as it collides with anything.
Certain compounds of ABS plastic may be virtually bullet proof but doesn’t save your figure when the shell is bending under the weight of someone’s foot. Yes the case didn’t break… But as for the contents….
So, your best bet is actually a case which can withstand someone standing on its corners. Your figures should all be boxed so they can withstand a brief attack.
For the more fragile tengu masks and unboxed figures, they should only be carried in your hand luggage. Be very aware of airline restrictions!