Tensei shitara Butouha Reijou!?: Koi Shinakya Shinjau nante Murige desu

Is this seriously the world of a "game?" If I don't romance one of the yanderes, I will die?! Before my reincarnation, I was a former delinquent and a top-class brawler nicknamed the "Crimson Rose" or the "Crimson Demon," who had gathered the interest of other delinquents. It was easier to talk with your fists than to talk about love, so naturally, my romance skills were zero. Despite this, it seems that I have reincarnated as a game's heroine, someone with a family of good standing and a gentle appearance! In order to protect my life while cooperating with the investigation of the incident, I will try my best to fall in love, but... The person herself hasn't realized it. Serina, the daughter of an Earl and a former delinquent, is cherished and loved by everyone around her. This is the story of her journey to obtain happiness. (Source: Shousetsuka ni Narou, translated)