Here is the full list of all 20 My Escort Company achievements.
Hire Umi
Hire Sora
One of your girl reached level 3!
Hire Nari
One of your girl reached level 2!
Hire Chio
Complete 50 requests!
Hire Mai
Hire Kanaye
Open a new Area!
Open 10 rewards/Spend 50 stars!
Hire Rini
Purchase an upgrade!
Unlock your first pose/outfit! Check the Gallery!
Hire Hayami
Unlock your first cutscene! Check the Gallery!
Unlock your first special video! Check the Gallery!
Finish the tutorial!
Hire Aki
Create your Escort Company