Why is it so hard to find any info on this. japan must have something for the newer systems like ps2 and dreamcast ...

I want to find code breaker or action replay codes for a handful of japanese games for the ps2 mainly the sega ages collection and the simple 2000 games.

i found a few codes people made(with an emulator) for the dreamcast games like under defeat.

Does any one here have any info on products like those above in japan?