Read manga: Jitaku Keibihime Terrass

manga
Summary:

Hilarious! The Hinomoto Kingdom's Princess Guard - an elite squad that directly protects their royal princess. Kasuga Haru was newly appointed to this prestigious position and was next to the Kingdom's one and only princess. There's only one problem. Their "royal princess" is a hikikomori, a recluse who stuffs her room with video games and refuses to leave even a nanometer out of her room. Kasuga's special mission given by the Queen is to make Princess Terras into a proper human. Can Kasuga succeed in turning this otaku princess into a proper princess full of charm and beauty