Unlock the following EX Chapters under the EXTRA menu by performing the corresponding tasks:

EX CHAPTER - HOW TO UNLOCK
EXCHAP 1 - Get the Good Ending in Chapter 1
EXCHAP 10 - Get the 2nd Ending in Chapter 5
EXCHAP 2 - Get the Good Ending in Chapter 3
EXCHAP 3 - Get the 6th Ending in Chapter 4
EXCHAP 4 - Get the Good Ending in Chapter 4
EXCHAP 5 - Get the 4th Ending in Chapter 5
EXCHAP 6 - Get the Good Ending in Chapter 5
EXCHAP 7 - Get the 8th ending in Chapter 5
EXCHAP 8 - Get the 6th Ending in Chapter 5
EXCHAP 9 - Get the Ending in EXCHAP6