How Do I Survive as the Villainess in an Otome Game?

Shen Mu stayed up all night watching his younger sister play an otome game because he couldn't sleep. The next day, he opened his eyes to find himself waking up in a bed eight hundred square meters in size. And just like that, he became a vicious male supporting character in the game. The game, Sakura Noble Academy, was full of over-the-top drama, but more importantly, it was set in a world of magic. The vicious male supporting character's original ending went like this: he framed the heroine, was exposed by her admirers, got expelled, was possessed by dark magic, and was cruelly purified until not even his ashes remained. The heroine was a gifted commoner, upright and kind, and unafraid of authority. Her admirers included, but weren't limited to, a sunny count's son, a gentle second prince, a cool-headed student council president, and an arrogant young master from a magical family. Thanks to his sister's expert playthrough, the heroine became entangled in everyone's affections, weathered misunderstandings, threats, and depression, reunited with them, and ultimately unlocked the 1-vs-many ending. Shen Mu: ...If I can't afford to mess with them, can't I just avoid them? Before the school year began, he decided he would stay far away from the heroine and cherish his life. Until he discovered that the heroine was his own younger sister! To protect his sister, he volunteered to take the blame for every scheme against her. As a result, late one night, her admirers took turns pinning him against the wall and asking through gritted teeth, "Do you like her that much?" Theme: Honesty and keeping one's word are admirable virtues.