Have all 11 Operations available in Omake. Purchase it for 500,000 Ten.
Gallery
Acquire all 16 epilogues (3 per Karte, 4 for Karte #5)
Omake options
Successfully complete the game. Allow the credits to complete and save when prompted to unlock the Omake optoins. You can now replay the mini-games and operations that were found during the main game, in addition to looking at gallery images and listening to music tracks. You can unlock all eleven operations in Omake by purchasing that option for 500,000 Ten. To unlock all gallery entries, you must unlock all sixteen epilogues.