Western Fantasy: The Princess Is Staying at My House and Won’t Leave

Aifan transmigrates to another world, where his younger sister takes in a girl who secretly ran away from home.

The girl is very strange. She stays at home all day, never causes trouble, and is remarkably hardworking.

Younger sister: "I heard that Her Highness the Princess secretly ran away from home half a year ago."

Aifan: "Forget about the princess. Come and see my latest inventions: a magic-powered mithril Iron Man, a magical smartphone, a hovering high-speed train, an anti-gravity passenger ark..."

Runaway princess: "I need to learn some maid's duties so I don't give away that I'm a princess."

Younger sister: "Big brother, stop researching nuclear magic bombs. I took in another girl today."

Aifan: "Come clean. Are you girls princesses?!"

Runaway princess: "I'm not leaving. You'd have to kill me to make me go."

This novel and its characters are entirely fictional. Any resemblance is purely coincidental. Do not imitate.