Here is the full list of all 13 Catgirls From My Sweet Dream achievements.
Compromise
Buy a return ticket
Speak with Lady Haruka
Visit Yumeko's Store
Collect 100 stars
Untie red ribbons
Date with Agnia
Taste Chocolates
5000 crystals in the wallet
Date with Miyuki
Taste Milkshake
Date with Sakura
Adventure begins here!