

Oh, I just read the Japanese wiki, and you're right. Apparently you get to play Komachi in Sakuya's final episode 0.0
When I enable the characters in 1 save, unless I hold it constant through an external application, they don't stay after the battle.
SO...
I've prepared a save for each chapter that has10000000 points/2000 WP/2000 Graze with all characters enabled at lvl 20 for every stage for Reimu and Marisa's routes in lunatic difficulty. You can choose the upgrade/skill/WP level for every battle. Note that points/WP graze might fluctuate depending on the save - no guarantees. This is kinda a backup for me too - so that I"ll have something ready when a new release comes out.
Here's the dl:
http://uploadmirrors.com/download/JFDYJYKK/hidden_character_saves.zipJust backup your old save folder and extract it in your save folder.
The save at savespot 99 is an "ultimate" save clear data for Marisa's route and has characters with 1000% upgrades, lvl100 unfocused movements, etc etc.
Note that most WP bonuses for the hidden characters don't work, except for lvl1 sakuya and lvl1-3 Komachi. And In the stages where new characters appear for the first time, the new characters will have old stats and not the lvl20 stats. Just how the engine works I'm afraid.
The hidden characters won't stay for your next battle, so if you want to keep playing, just load the next save after you finish the battle.
There may be some overupgrades that slipped by, though I changed back what I could. They were done for testing purposes, so it's your choice whether to use them or not.
I included my sys save too, in case they aren't compatible with uncleared games. Side effect is Sakuya's route should be open from start, but eh. If you're downloading this you aren't adverse to spoilers, amirite?
If you guys can use these saves to update information on the wiki regarding the statistics of the temporary playable characters, I'd appreciate it.
These were all done with testing in mind. Any comments about "cheating" will be ignored.
I take no responsibility if these saves cause any adverse affects on your game.