I Was Reborn as the Throwaway Prince's Maid?!: I'm Just a Background Character, so Why Is My Life Suddenly So Chaotic?! All right... I won't let him break off his engagement with the heroine!

Tina is a maid who remembers that she played a video game that contained this world in her past life. But she's not just any maid... she works under the throwaway character Prince Viself who's fated to die as the kingdom falls into ruin! Now she's on a mission: save the kingdom by ensuring Prince Vi...

Source: MyAnimeList