I've Been Killing Slimes for 300 Years and Maxed Out My Level

A charmingly low-stakes isekai comedy from Yen Press, I've Been Killing Slimes for 300 Years and Maxed Out My Level follows a former office worker who, after reincarnating as an immortal witch, spends centuries in peaceful slime-hunting—only to discover she's accidentally become the world's most powerful being. The series, adapted from the light novels by Kisetsu Morita and illustrated by Yusuke Shiba, revels in the humor of an overpowered protagonist who just wants a quiet life, only to attract a growing family of quirky adopted daughters and curious new friends. Its gentle, slice-of-life tone and warm character dynamics have made it a standout in the crowded isekai genre, offering a refreshingly relaxed take on fantasy adventure.