Here is the full list of all 17 Negligee achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Complete all endings for the Game
Unlock all of the games Epilogues
Complete the games ultimate Harem ending
Pick Perfect Outfits for Yuuki & Melissa
Hire Charlotte during the Interview
Unlock the Bonus Epilogue for Sophie
Unlock the Bonus Epilogue for Jasmin
Unlock the Bonus Epilogue for Charlotte
Select Charlotte for the Permanent Position
Unlock Charlotte's Bad Ending
Unlock Jasmin's Bad Ending
Unlock Sophie's Bad Ending
Get Fired from the Store
Hire Jasmin during the Interview
Hire Sophie during the Interview
Select Jasmin for the Permanent Position
Select Sophie for the Permanent Position