Akuyaku Reijou nanode Last Boss wo Kattemimashita

Being acutely ill, a young girl has spent most of her life in a hospital room playing otome games to fill her time. However, she one day finds herself in the midst of a scene from one of these games as the storys villainess, Irene Loren DAutriche. At the banquet to celebrate the end of the academys winter term, the crown prince and Irenes childhood friend, Cedric Jeanne Elmeier, publicly annuls his engagement with Irene and announces that he is in love with Lilia Rainworth, the games female protagonist. Aware of the tragic future ahead of her and determined to change it, the young girl resolves to conquer the games final boss, the "Demon King" and Cedrics half-brother, Claude Jeanne Elmeier, by making him fall in love with her instead. With time running out, can Irene succeed with her plans, or will she remain bound to the ill-fated ending that awaits her?