Tensei Oujo wa Kyou mo Flag wo Tatakioru

Synopsis

I was reborn as a princess in the world an otome game with memories of my previous life. Wait, what? I'm the heroine's love rival? You're kidding! I have no intention of falling in love with any of those pathetic guys, because the one I like is a support character, the Commander of the Royal Knights. Except the Heroine, after being reincarnated in this shitty game where the support characters are way better than the love interests, is threatening to bring down my own life with flags, and I am determined to strike them down. (Source: Shousetsuka ni Narou, translated)