Continuing with the anti-IWM-register crusade, our next subject is Sensei, a wonderful karate choppin' game by F.U.C.K. Beyond its initial-stage loader, it uses its own de-nibblizing routines that appear distinct from the FTA/ACS ones we saw earlier. And it doesn't use TCS Cruncher, although some of its code/data is compressed with simple RLE (Byte Slasher) and PackBytes. Fortunately the second-stage loader itself isn't obfuscated. I spent plenty of time taking this apart and attempting to understand it, and I can save you several hours if you care to read:

Sensei Loader Disassembly Notes

Fortunately, once you get a feel of what everything's doing, the fix is way too easy:
Booting on emulators as well as ROM 3 + CFFA3000 results in a fun game with full intro.

Known issue with High Scores, to be addressed in a future update

Download patched Sensei image (right-click, Save As, etc)