Kami wa Saikoro wo Furanai

When Kanau was a little girl, her father believed she would grow up and marry someone, leaving him behind. He unintentionally wished that his daughter would remain little forever and so, at the age of 23, Kanau still has the body of a primary schooler. However, a robot left behind by her father tells her of the 6 Caramel Dice's, which, if gathered, would grant the holder one wish.