Manga by author Mizusato Yuuki

IZechshave a little sister. Her name is Caron, and she's so precious to me I couldn't love her more.But if things continue as they are, she's doomed to die a tragic death.Why? Because this world is exactly the same as the RPG-style romance game I played obsessively in my past life.And in every route, no matter what, Caron's fate ends in death.There's no way I can let my beloved little sister meet such a cruel end!That's whyI'll fight back against fate with everything I've got!