I've Got A Mana Processor In A Magic World - Chapter 11: Magic Theory

In her previous lifetime, they had married for five years. He meant everything to her, but she was thrown away like an old shoe.

After her rebirth, she gave him a divorce contract preemptively—

“Divorce after one year, the terms of the contract are as follows: husband and wife shall not share a room or bed. Intimacy forbidden?”

He raised his eyebrow.

Who knew that after she got drunk one day, leaning on the headboard, he rested his deep-set eyes on her. “You broke the contract, Mrs, Li.”

- Description from Novelupdates

At the Tristain Magic Academy, her classmates call bumbling witch-in-training Louise Francoise le Blanc de la Valliere “Louise the Zero.” During an important coming-of-age ritual, when each student must summon their own witch’s familiar, Louise confirms her classmates’ opinion by accidentally conjuring up a normal teenage boy from Japan. Whether the two of them like it or not, the laws of magic bind them as master and servant forever! A hilarious novel with romance interwined.