Final Fight One Gameshark Codes (Japan)
This page contains Gameshark cheat codes for Final Fight One (Japan). If you're playing on an emulator you can usually input codes very easily by accessing a tab off the top of the toolbar. Anyone playing on a physical Gameboy will need to purchase a physical Gameshark device to use these codes.
If you're using an emulator and still can't figure out how to setup these codes, you're in luck! There's two common emulators for GBA games, the mGBA and VisualBoy Advance. Follow the link provided for the emulator you're using to be taken to a guide explaining how to get these codes working.
Invulnerability: 7DFF610B E62576B2
Unlimited HP: BB0AE80F 77C48E89
Unlimited Lives: CC12DE1A 9AB77804
Unlimited Time: DA2248F2 E3F0F017
Max Kills: EC999564 5E286303