That is how naval bases work so it is possible in the sense that it isnt against the rules however it would require miracle dice to pull off combined with an inept US player.
First you would have to take out the US fleet which is easy.
Then you would have to take Hawaii so that you could reach western US.
Hawaii has 2 infantry 1 bomber 1 tac 1 ftr
None of Japans planes can reach land so japan would only be able to attack with 2 transports from Japan (2 inf 1 art and 1 arm) and 1 transport from carolines ( 1inf). Possible but would need pretty good dice.
So all that is certainly possible.
Then the US has its fleet at sz 10 which maybe you could destroy.
Then assuming you lost no units from the invasion of Hawaii you would have 3 inf 1 art 1 arm vs 4 inf 1 art 1 arm 1 bom 3 ftrs 1 tac bomber (9 v 29) which would be assuming the US didnt purchase anything round 1 which wont be the case.
So the only chance would be if you got lucky and captured hawaii and then the US player abandoned West USA without a fight.
Would be a suicide assault and would absolutely cripple Japan.