Here is the full list of all 17 Open At Nine achievements.
Failed to repay your debt
Reach max level on all Monster Girls
Reach max lust rank on all Monster Girls
Earn a total of 80000 coins
Use Refusal Voucher for a total of 10 times
Finish all the H-events
Reach the End Credits
Get Abel IX's balls empty
Use Revival Herb for a total of 10 times
Build all 6 rooms (any type)
Build all types of rooms at least once
Sign contracts with all the Monster Girls
Use potion items for a total of 50 times
Sign contracts with Oriana and Kamaria
Add a room for the first time
Sign a contract for the first time
Open your business for the first time