Among the collectibles in Onimusha: Way of the Sword, one type you can find is Genma Notes. These are a series of files found inside specific chests that provide additional information about the enemies you encounter.
For enemy entries covering foes you fight multiple times, the entries are updated with new variants as you defeat them.
Warning: this section contains unavoidable spoilers in the form of enemy and boss names.
As mentioned above, all Genma Notes are found inside specific Treasures:
