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

I've Been Killing Slimes for 300 Years and Maxed Out My Level is a fantasy comedy about an immortal witch who achieves maximum power through the most mundane means possible. After her reincarnation, the protagonist spends three centuries living a quiet life in the countryside, casually defeating slimes for income. Without realizing it, this routine accumulates enough experience to reach level ninety-nine, making her the strongest being in existence despite never seeking adventure or combat.

The series aired as a twelve-episode TV season in spring 2021 and has finished airing. It blends adventure and slice-of-life storytelling, balancing comedic situations against a fantasy setting. The premise attracts viewers who enjoy overpowered protagonists played for laughs rather than drama, alongside those seeking lighthearted fantasy without high-stakes conflict. The witch's growing entourage—including curious adventurers, a dueling dragon, and a monster girl who sees her as a mother figure—creates much of the show's humor.

This series suits anyone tired of traditional adventure narratives where power comes from struggle and determination. Instead, it explores what happens when someone becomes extraordinarily powerful while genuinely wanting nothing to do with it, treating strength as an accidental byproduct of just trying to pay the bills.