you cant
You're in the Kanto region in LeafGreen and FireRed.
like when i was playing soulsilver (jotho reigon) i kept find kanto Pokemon (caterpie, tec.) why?
hoen
Kanto.
kanto
Not possible.
no ...
there is no way you can reach the hoenn region.
not possible.
you dont, kanto is the only region
you are already in the kanto region when you start the games
in firered and leafgreen you play in the kanto region