Azusa Aizawa died at her desk. That is the premise of I’ve Been Killing Slimes for 300 Years and Maxed Out My Level, and it is a premise that refuses to let her rest. After dying of overwork in the real world, Azusa is reincarnated as an immortal witch in a fantasy realm, where she spends three centuries slaying slimes for a living. The result is a comedy about a woman who has maxed out her level without ever meaning to, and a show that turns the genre’s usual quest narrative on its head.
The series premiered on AT-X on April 10, 2021, and ran for 24 episodes across two seasons, concluding on June 21, 2025. It is an adaptation of a Japanese light novel series by Kisetsu Morita, illustrated by Benio, which first appeared online in 2016 on the user-generated publishing site Shōsetsuka ni Narō. The anime is produced by Revoroot for the first season and Teddy for the second, and it carries a cast led by Aoi Yuuki as Azusa, with Kaede Hondo, Sayaka Senbongi, Minami Tanaka, Sayaka Harada, Manami Numakura, Riho Sugiyama, Azumi Waki, and Yukari Tamura rounding out the main voices.
Trailer, via Crunchyroll.
Azusa’s Simple Life
Azusa’s story begins in the real world, where she is a Japanese office worker. She dies from overwork, and the goddess who oversees her reincarnation places her in a fantasy realm as an immortal, unaging witch. Her vow is simple: she wants a pleasant, stress-free life. The easiest way to make money in this world is to hunt slimes, the weakest monsters available, and she spends three centuries doing exactly that.
The humor comes from the contrast between her intentions and the results. Azusa is not a hero seeking glory. She is a woman who wanted a quiet life and got the opposite. By slaying millions of slimes, she accumulates vast amounts of experience points, and she reaches level 99 without ever realizing it. The show tracks her journey from a humble hunter to a legend, but the tone stays light throughout.
Azusa’s nickname in the series is “the Witch of the Highlands,” a title she earns through sheer longevity. She is voiced by Aoi Yuuki, and the performance captures her weariness with the world around her. She is wary of overwork and excitement, having died from both in her previous life. Her protectiveness toward her adoptive family and friends is a genuine arc, and it is one of the reasons the show works.
“I’ve never been on an adventure, but I’m the strongest in the world… What’s going to happen to my relaxing life?!”
That line sums up the whole series. Azusa is the strongest person in the world, but she has never been on an adventure. The show delights in the tension between those two facts.
Laika and the Dragon’s Defeat
Laika is the first major character to arrive in Azusa’s life. She is a roughly 300-year-old shape-shifting red dragon girl, originally arrogant and eager to prove herself. She comes to Azusa to fight her and establish her superiority, but she gets soundly beaten. The defeat changes everything.
After being bested, Laika joins Azusa as her first apprentice and housekeeper. Over time, she becomes her adoptive younger sister. The relationship is central to the show’s emotional core. Laika’s rivalry with Fratorte adds a layer of friction, but the bond between Azusa and Laika remains the heart of the series.
Kaede Hondo voices Laika, and the performance brings a sharp edge to her initial arrogance before it softens into loyalty. The show handles the transition well, showing Laika’s growth through small moments rather than a sudden shift.
The Slime Twins
Falfa and Shalsha are the elder and younger twin sisters, both slime spirit girls. They are reincarnations of the slime creatures that Azusa killed for a living. Their relationship with Azusa is complicated. Shalsha is deeply resentful toward Azusa at first, but Falfa adores her and considers her their “mother.”
Sayaka Senbongi voices Falfa, and Minami Tanaka voices Shalsha. The dynamic between the twins provides some of the show’s most touching moments, particularly when Shalsha learns to accept Azusa despite her past. The show uses the twins to explore themes of forgiveness and acceptance, and it does so without heavy-handed moralizing.
The Adventurers Arrive
As rumors of the level 99 witch spread, Azusa finds herself besieged by curious adventurers, duelist dragons, and even a monster girl calling her mother. The show’s premise is that Azusa is the strongest person in the world, yet she has never been on an adventure. The arrival of these characters forces her to confront the attention she never sought.
The show handles this wave of visitors with a mix of comedy and exasperation. Azusa is bewildered by the attention, and the audience shares her confusion. The show does not mock the adventurers so much as it mocks the idea of fame itself. Azusa did not seek this path, and the show keeps reminding us of that.
A Second Season and Beyond
The second season aired from April to June 2025, continuing the story of Azusa’s increasingly complicated life. The show explores the consequences of her immense power, and it raises the question of what happens when a legend cannot escape her own reputation. The series has also spawned various spin-off novels, expanding the world beyond the main story.
The second season builds on the foundation laid in the first, deepening the relationships between Azusa and her companions. It introduces new challenges while maintaining the show’s core tone. The pacing holds together across both seasons, and the animation remains consistent throughout.
The Verdict
I’ve Been Killing Slimes for 300 Years and Maxed Out My Level succeeds because it takes a familiar setup and turns it inside out. Most isekai stories feature a protagonist who seeks power to change their fate. This one features a protagonist who sought nothing and got everything anyway. The humor comes from the mismatch between Azusa’s intentions and the results of her actions.
The show is not without its flaws. Some plot threads are resolved too quickly, and the pacing occasionally drags in the middle of episodes. The comedy can also lean on repetition, with jokes about Azusa’s level and her lack of excitement becoming familiar by the later seasons. These are minor complaints, however, and they do not detract from the show’s overall achievement.
Azusa’s journey is a refreshing change of pace in a genre often defined by quests and battles. She is a woman who wanted a quiet life and ended up being the strongest in the world. The show respects that contradiction, and it makes the ride worthwhile.
Score: 7.8 of 10.
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