Here is the full list of all 16 Cupid Story: First Date achievements.
Complete the mission without shopping even once
Beatrice becomes Daniel's girlfriend
Achieve maximum level in a relationship
Sleep through a whole day
Claire becomes Daniel's girlfriend
Obtain 4000 Love
Use 20 items
Complete all dialogues with a girl
Gift a girl something that already belonged to her
Sell to Graciel an item that belongs to a girl
Anna becomes Daniel's girlfriend
Unlock the secret skill Confession
Make all 3 girls fall In Love with Daniel in a single run
Buy all items in the Shop in a single run
Discover all the information and collect all the items in the 3 girls' rooms in a single run
End a date with full HP