Astraea, the strongest swordsman in the world. One day, she realizes that she has been reincarnated as a character inside a book. And not just any side character, but the one destined to be killed by the final boss, the god of darkness. But during a hike in the mountains, she saves a young boy from assailants... only to discover he's destined to become that god of darkness. 'Fine, then! If it's comes to this, I'll raise him myself and reform him completely!' So she ends up taking him in and raising him... "Raea, where are you going? Are you off to see that guy again?" What was once a kid I tried to save has grown into an obsessive man who follows me everywhere and watches my every move. Somehow... it feels like I've raised him wrong.