Hi and welcome. As strange as it sounds, you aren’t missing pieces. Not all powers have the same number of units, and Japan only gets 4 bombers in the box. If you want more there are places to order pieces online, such as historicalboardgaming.com, though I’m not sure if they ship to every country. I don’t have any issues with running out of pieces in this game though. Hope you enjoy it!
Thanks for answer. I knew that historical board gaming because i have 1941 too and i tried to get more chips and units for it. 17$ shipping cost is too expansive but yes, they are shipping everywhere.