Waltz with My Demon Lord

Luna Xia summoned a devil to help retaliate against her classmates. However, she never expected to summon the Devil King! Suddenly, Luna's life starts to take off on a crazy roller coaster of events! Along the way, they attracted a succubus, angel, and knight. They jumped right past Luna's skepticism and went straight for the gas pedal!
Devil King Lucifer: Romance can't be romantic. How can it ever be romantic?
Luna: Can I return the product?
We don't accept returns. Please use with ease.

(Source: AC.QQ, translated)