Here is the full list of all 94 Hentai Pair achievements.
Easy One
High Five
10/10
I found it!
I am the best!
1/10
2/10
3/10
4/10
5/10
6/10
7/10
8/10
9/10
Level 1
Level 2
Level 3
Level 4
Level 5
Level 6
Level 7
Level 8
Level 9
Level 10