From mangaupdates:

Born into a wealthy family, she lost her mother at a young age.
She is Riona, a girl who was raised by a single father.
At the girls' school she attends, she has many friends and a special partner of hers,
She lives feeling a little lonely that her busy father has just left her house.

One day, her father bought a robot that she said was her "housemaid"
She witnessed the act of "Folty"...?

A girl who wants her affection and a robot who doesn't know her feelings.
A dramatic story of gems!