MaryahLu

"Why do the main character's parents often get the short end of the stick?"
That is what Mila asked while looking up at the sky. She was grumbling toward whoever sent her inside the novel she read before she died.
She becomes the mother of the main character, whose parents are both dead. Mila's character was merely a tool for the MC's character development.
It's a simple, fix-all solution. The author wanted to make the audience instantly sympathetic towards the main character, and the best thing he did was to have the MC's parents die.

After she avoided her death in the original plot, death flags kept coming for her. 

Will the original plot not end if she's not dead?

....

proofreader: Aserehtam

Main character's parents must die

"Hey, you don't understand us. Why did you say you'd stay here?" Sabrina asked Robert.

She casually speaks to Robert, even if they can't speak each other's language.

"You should have come home. You'll only trouble us."

Sabrina speaks as if Robert is not welcome at their place, but her expression contradicts her words.

Her animated eyes gleam as she stares at the black card in her hand. She even swirled and danced around, even without music.

Robert doesn't get what kind of value the black card has, but it instantly made Sabrina make him stay at their restaurant. It was the card that Luther used to convince Sabrina to take care of Robert.

Still reluctant to help Robert, Luther was glad to hear that Robert didn't want to stay at his house, either. Instead, Robert suggested he work at the Japanese restaurant as he planned to learn this world's common sense with actual experience and refused to be taught by Luther or the others.

"Fighting someone."