If you’ve been eyeing this cozy series and wondering whether the I’ve Been Killing Slimes for 300 Years and Maxed Out My Level manga is finished, here’s the short answer: not yet — but the end is in sight. The manga has been announced to end with its 19th volume. Maybe you want to know if you can binge the whole thing from start to finish, or maybe you’re trying to figure out how many volumes you’d need to collect. Either way, this guide covers everything you need to know.
For some quick context: this series falls into a genre called isekai, which is a Japanese term for stories where a character is transported or reborn into another world — usually a fantasy setting. It’s one of the most popular genres in manga right now, and Killing Slimes for 300 Years is a fan-favorite example because of its relaxed, feel-good tone.
Not Yet — Killing Slimes for 300 Years Manga Is in Its Final Stretch
The manga is not finished yet. I’ve Been Killing Slimes for 300 Years and Maxed Out My Level is still publishing new chapters in Gangan ONLINE — a Japanese online manga magazine where chapters are released on a regular schedule before being collected into printed books (called volumes). In August 2026, it was announced that the series will wrap up with Volume 19.
As of 2026, the Japanese edition has reached 18 volumes, published under Square Enix’s Gangan Comics ONLINE HOME label. The English edition, published by Yen Press, currently sits at 16 volumes — with Volume 16 having released in May 2026.
So if you were holding off until the series was complete, the Japanese edition is only one volume away, while the English edition still has a few to go. The good news? This is a slice-of-life comedy that’s easy to pick up and enjoy volume by volume without needing a finished storyline to feel satisfied.
Where the Story Stands Right Now
The manga is written by Kisetsu Morita (adapting the original light novel) with art by Yusuke Shiba and character designs by Benio. In manga, it’s common for different people to handle the writing, illustration, and character design — especially when a series is based on a novel.
The premise follows Azusa Aizawa, a former overworked office worker who dies and gets reincarnated — reborn — as an immortal witch in a fantasy world. Her new life plan? Take it easy. Kill a few slimes every day. Live peacefully in the highlands.
Of course, 300 years of casually killing slimes adds up, and Azusa accidentally maxes out her level — which draws all sorts of attention from dragons, demons, spirits, and other colorful characters who gradually become part of her chosen family circle. Think of it as a story about building a warm, quirky household one stranger at a time.
For most of its run, the series has followed an episodic structure: rather than one long continuous plot, each volume delivers its own batch of fun with relatively self-contained stories. That means you don’t need to worry about cliffhangers or complicated storylines carrying across dozens of books.
Two seasons of the TV anime have also aired (Season 1 ran for 12 episodes), which has brought a lot of new readers to the manga. If you came from the anime and want more Azusa, the manga has plenty of material waiting for you.
How Many Volumes Are Out — Japan vs. English
Here’s the current breakdown:
| Edition | Volumes | Publisher | Latest Release |
|---|---|---|---|
| Japanese | 18 | Square Enix | Volume 18 — August 2026 |
| English | 16 | Yen Press | Volume 16 — May 2026 |
The English edition trails the Japanese release by a few volumes, which is standard for most manga translations. Yen Press publishes the series in both print and digital formats, so you can read however you prefer.
If you’re building a physical collection, a complete English set right now means Volumes 1 through 16, with more volumes expected as the English edition catches up to the Japanese release. There’s no box set available as of this writing, so you’d be picking up individual volumes.
Volume 1 is a great entry point — it gives you a clear sense of whether the tone and humor click for you before committing to more. You can find individual volumes at major retailers including Amazon, Barnes & Noble, and digital platforms like BookWalker.
I've Been Killing Slimes for 300 Years and Maxed Out My Level, Vol. 1 (manga)
Is the Source Light Novel Already Finished?
First, a quick explainer: a light novel is a style of Japanese novel — typically short, fast-paced, and illustrated with a few anime-style images. Light novels are different from manga (which tells the story primarily through sequential artwork and dialogue panels). Many popular manga series, including this one, are adaptations — meaning the manga re-tells a story that originally existed as a light novel, with its own pacing and visual storytelling.
The manga adapts a light novel series, also by Kisetsu Morita. The light novel has been announced as ending with its 30th volume, per a report from Anime News Network in January 2026. The light novel runs well ahead of the manga in terms of story progress, so readers who want to get further in the story — or experience the conclusion before the manga reaches it — have that option.
The light novel is published in English by Yen Press, making it accessible to English-speaking readers. Keep in mind that the manga and light novel are distinct experiences — the manga has its own pacing and visual storytelling, while the novel goes into more detail on certain events and characters.
There are also spin-off manga in the franchise — separate, related stories set in the same world that aren’t continuations of the main storyline. The Red Dragon Academy for Girls and I Was a Bottom-Tier Bureaucrat for 1,500 Years, and the Demon King Made Me a Minister are two examples. Think of spin-offs as bonus content: they share the same universe but have their own characters and plots. You don’t need to read them to follow the main series at all.
Where to Start Reading in English
Getting into this series is refreshingly simple:
- Start with manga Volume 1. The series follows straightforward numbered order — Volume 1 through 16 as of now, with more on the way. Each volume is a collected book of manga chapters, typically around 150–180 pages.
- Spin-offs are separate. You don’t need to read The Red Dragon Academy for Girls or any other side series to enjoy the main manga. They’re standalone and optional.
- Print or digital — your call. Both formats are available through Yen Press at major retailers.
- Rated T (Teen) by Yen Press, which is similar to a PG-13 movie rating. The content is lighthearted comedy and fantasy — no heavy violence or mature themes to worry about.
If you’re coming from the anime, you could either start from Volume 1 for the full experience or try to find roughly where the anime left off. Starting from Volume 1 is the safer bet — you’ll catch details and scenes the anime may have trimmed.
FAQ
Is the Killing Slimes for 300 Years manga finished?
The manga has been announced as ending with its 19th and final volume. As of this writing, 18 Japanese volumes have been released, with the final volume still to come. The English edition from Yen Press is at 16 volumes and continuing to catch up. You can start collecting now with the end of the series in sight.
When will the Killing Slimes for 300 Years manga end?
The manga was announced in August 2026 as ending with its 19th volume. Volume 18 released in Japan in August 2026, so the final volume is the next installment to come.
How many English volumes are there?
16 volumes from Yen Press as of May 2026, available in print and digital formats.
Is there an anime adaptation?
Yes. Two TV anime seasons have aired. Season 1 ran for 12 episodes. If you enjoyed the anime, the manga covers the same story and continues further.
Do I need to read the light novel before the manga?
Not at all. The manga is a self-contained adaptation — it re-tells the light novel’s story in comic form. You can read it without ever touching the light novel. The light novel is there if you want to read ahead or experience a different version of the story, but it’s entirely optional.
Can I start the manga after watching the anime?
Absolutely. Since the manga follows straightforward volume numbering, you could either start from Volume 1 for the full experience or try to find roughly where the anime left off. Starting from Volume 1 is the safer bet — you’ll catch details the anime may have trimmed, and the comedic pacing in manga form has its own appeal compared to the animated version.