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 "Forty"...?

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

Two childhood friends, a boy and a girl, used to share a secret magic. Now that they're in high school though... A story of secret love from an outstanding writer.