Originally Posted by
dvs7310
I guess my actual confusion is whether my allowance is 40kg, or is it 20kg + 20kg (meaning must be no more than 20kg per bag?)
32kg max per piece is industry standard and is also mentioned here:
https://www.jal.co.jp/jp/en/dom/fare/f_bag/
This is to help ensure airport staff will not be injured.