Unlock Hard Mode
Finish the game once to unlock hard mode.

Unlock BGM Test
Finish the game on normal.

Unlock Continue Mode
Finish the game on normal. With the cleared file on a memory card, start a new game and when asked, load the cleared file's data to "carry over" the stats, weapons, and items (includes Amahagune) accrued from the file.

Unlock Movie Gallery
Finish the game on normal.

Unlock Voice Test
Finish the game on normal.