Hello everyone. Since this appears to be the only English page discussing SoftDenchi Wrapper (and fairly recently too), I'll give you guys some of the information I have.
I have reverse engineered the portion of the wrapper that matters, and have made an unwrapper that should be able to unwrap versions 1 through 7. But before I present that, here's what I think about SoftDenchi. Quite frankly, the wrapper system is very weak. I don't know if Paltiosoft is underestimating people, or if they're incompetent, but the wrapper presents little challenge to anyone wishing to unwrap, especially if they've already gotten a valid activation key. The wrapper's protection is encrypting a portion of the protected EXE's code, but the amount is so small it's almost meaningless. In the v7 sample I have 32 bytes are encrypted starting at the entry point. If you know about reverse engineering, you will know that the entry point typically contains the runtime initializer, and this code is similar between many executables using that runtime. So it's possible to just find another EXE with similar code, copy it over, fix a few offsets, and you're done. Exit, from above, is v6, and only had 16 bytes encrypted. There is no anti-dump, so you can just run the game, dump process, and copy over the unprotected bytes. Not only that, but the wrapper uses a publicly available PRNG implementation, and using that to perform XOR encryption. (It's a good thing they did that, because it meant less work for me. I wonder what the period on the PRNG is.) The wrapper has no support for in-memory patching of EXEs with TLS nor relocations. And you can practically skip all of its licensing checks by jumping past those instructions (and it'll decrypt and launch the game, with enough time for you to do a memory dump). Overall, it's just braindead and rather pathetic. You don't even need a code to decrypt it. If this is what company that made "the #1 DRM system used in Japan" can come up with, I think it is rather insulting to the Japanese.
OK, enough technical details. I know you want the unwrapper. So find it here:
Unwrapper + source code:
http://www72.zippyshare.com/v/3lDaTxF5/file.htmlUpdate June 2, 2015: Changed output file name encoding to default.
To use, just drag and drop the protected EXE on to the unwrapper EXE, and it'll do its work. You may see a (EXE name)_unwrapped.exe file which will be the unwrapped version, or nothing, if they don't use an embedded EXE. Check the unwrapper's output for details.
If you encounter any EXE that doesn't unwrap properly, send them my way and I'll take a look for you.