Akutou Ikka no Manamusume, Tensei-saki mo Otome Game no Gokudou Reijou deshita. Saijoukyuu Rank no Akuyaku-sama, Sono Dekiai wa Fuyou desu! @comic

After her sudden death at the hands of an assassin, the former granddaughter of a yakuza boss reincarnates in an otome game as the heroine. The game is, of course, set in the time of early European mafia (but with magic), specifically a kingdom where the royal family is supported behind the scenes by five major gangsters! A dangerous love game between a former yakuza heiress and her villain fiancé begins! (Source: TO Books, translated)