Tenseisha no Watashi wa "Oshikatsu" Suru tame Seijo ni Narimashita!

Eristella has been reincarnated into the world of a game she played in her previous life. To save her absolute favorite character—Adolf, a knight captain who’s doomed to die—she rises through the ranks, becomes a Saint, and even enters into a contract marriage with him! Now that they live under the same roof, will she be able to save Adolf?! (Source: Manga UP!) Note: Includes five extra chapters.