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