This guide is specifically for unlocking the special missions. I'm preeeetty sure you need an 'A' ending for them all. This guide is for 'A' only.
This walkthrough is meant to be followed in order in order to get the special mission at the end.
Louise: Mission 4 - The Man Driven Mad by an Angel
- Private Tutor --> Go all the way --> Berate --> "A"
Kia: Mission 6 - A Blasphemy Before God
- Reply --> Look --> Altar --> "A"
Kia: Mission 2 - The Selfish Prince Holiday
- Bodyguard --> Don't take his clothes off --> Use press --> Teach him --> Fight --> Nibble --> "A"
Kia: Mission 3 - The Gay Man's Trap
- Block it --> Can't trust --> Feign Ignorance --> Check again --> Blow it up -