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I've Been Killing Slimes for 300 Years and Maxed Out My Level 2021

★ 7.8/10 · 240 votes TV-14 AnimationComedySci-Fi & Fantasy 2 seasons · 24 eps Ended
Where to watch: CrunchyrollCrunchyroll Amazon ChannelAmazon VideoApple TV Store
Quick answer

What is 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 an anime television series that premiered in April 2021. The story follows a woman who dies from overwork in the real world and is subsequently reincarnated as an immortal witch.

Type
TV series
Year
2021
Status
Ended
Episodes
24
Runtime
24 minutes
First aired
Apr 10, 2021
Last aired
Jun 21, 2025
Original language
JA
Origin
JP
Networks
AT-X
Genres
Animation, Comedy, Sci-Fi & Fantasy
Updated
Availability by region

Where to watch

Stream

CrunchyrollCrunchyroll Amazon Channel

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Apple TV Store
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Estimate the schedule using 24 episodes and an average 24-minute runtime.

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Overview

I've Been Killing Slimes for 300 Years and Maxed Out My Level is an anime television series that premiered in April 2021. The story follows a woman who dies from overwork in the real world and is subsequently reincarnated as an immortal witch. Seeking a peaceful existence, she spends three hundred years living a relaxing life while killing slimes to earn money. Over time, these activities unintentionally grant her enough experience points to reach level 99, making her the strongest being in the world. Her status as a powerful witch eventually attracts unwanted attention, leading to visits from curious adventurers, duelist dragons, and a monster girl who identifies her as a mother figure. These events threaten to disrupt the quiet life she has cultivated. The series adaptation was confirmed in October 2019 and features a voice cast that includes Aoi Yuki and Kaede Hondo. The show is available for streaming on platforms such as Crunchyroll and Netflix. The original creator of the source material is Morita Kisetsu.

witchmagicslimeimmortalityreincarnationslice of lifeanimeother worldsword and sorceryisekaibased on light novelgentle
Sources & verification 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 I've Been Killing Slimes for 300 Years and Maxed Out My Level Slime Taoshite 300-nen, Shiranai Uchi ni Level MAX ni Nattemashita How Archytele verifies pages
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Should you watch it?

“A reincarnated immortal witch accidentally becomes the world's strongest by killing slimes for 300 years.”

# slice-of-life# fantasy# comedy# isekai# relaxed
Reasons to watch
  • Unique take on the overpowered protagonist trope
  • Gentle humor and wholesome interactions
  • Creative world-building around mundane activities
Keep in mind
  • Slow pacing may not appeal to action seekers
  • Some repetitive elements in early episodes

You enjoy low-stakes fantasy with a strong female lead.

Suitable for teens and up, with mild fantasy violence and comedic situations.

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Cast

Aoi Yuuki Azusa (voice)
Kaede Hondo Laika (voice)
Sayaka Senbongi Falfa (voice)
Minami Tanaka Shalsha (voice)
Sayaka Harada Halkara (voice)
Manami Numakura Beelzebub (voice)
Riho Sugiyama Rosary (voice)
Azumi Waki Fratorte (voice)
Yukari Tamura Pecora (voice)
Sakura Nakamura Effect Voice (voice)
Shinya Takahashi Villager A (voice)
Ari Ozawa Vania (voice)

Episode guide

Season 1 · 12 episodes Open the complete Season 1 guide →
Season 2 · 12 episodes

Frequently asked questions

Is this series based on a manga or light novel?

Yes, it's adapted from a Japanese light novel series written by Kisaki and illustrated by Shiryu.

What makes the main character so strong?

She gained immense power through 300 years of continuous slime-killing, accumulating experience points unintentionally.

Does the series have a lot of action scenes?

While there are some combat moments, the focus is more on daily life and character interactions.

Is the tone serious or comedic?

The series blends both, with a generally lighthearted and humorous approach to fantasy tropes.

How does the main character interact with others?

She attracts various followers and companions who seek her out due to her legendary status.