So you want to read That Time I Got Reincarnated as a Slime (転生したらスライムだった件 — the original Japanese title) but the sheer number of volumes and spin-off series has you staring at a bookshelf in mild panic? Totally fair. Here’s the short answer for your manga reading order: read the main manga, Volumes 1 through 29, in numbered order. That’s the whole core path.
But there’s more to know — multiple spin-off manga, a light novel series (the original prose version of the story), and several anime seasons all orbit this franchise. If you want the full picture on what to read, when to read it, and how to do it without wasting money, keep going. It’s all below.
For anyone wondering whether this series is worth that kind of commitment: this is the story of Satoru Mikami, an ordinary office worker in Tokyo who gets fatally stabbed and wakes up reincarnated as a slime in a fantasy world. What starts as a comedic survival story evolves into a sprawling tale of nation-building, politics, and increasingly high-stakes battles. The combination of a likable lead character, genuinely clever world-building (the way the setting and its rules are constructed), and a story that keeps escalating has made this one of the most popular isekai — a genre built around characters transported or reborn into another world — manga running today.
The Simplest Reading Order for That Time I Got Reincarnated as a Slime Manga
Here’s the bottom line: read the main manga, Volumes 1 through 29, in numbered order. That’s it. That’s your reading path for the entire core story as of early 2026.
The main manga is written by Fuse (伏瀬) and illustrated by Taiki Kawakami (川上泰樹), with character designs by Mitz Vah (みっつばー). It’s published in installments in Monthly Shonen Sirius, a manga magazine from the Japanese publisher Kodansha (“shonen” refers to manga aimed at a teenage boy audience, though readers of all ages enjoy it). The manga faithfully retells Fuse’s original light novel — a type of short Japanese novel with some illustrations — in comic form. This manga is the backbone of the entire franchise. Every spin-off, every anime season, and every movie branches off from this trunk.
The series is ongoing. As of March 2026, there are 29 English volumes available (published by Kodansha in English), with 32 volumes released in Japan. So English readers are a few volumes behind, but the gap isn’t huge.
Your core reading path is clean and simple: Volume 1 → Volume 2 → Volume 3 → … → Volume 29, straight through in numbered order. No detours required.
Every spin-off manga is optional — none of them contain information you need to understand what’s happening in the main series. If you want to keep things simple, you can stop reading this article right here, grab Volume 1, and go.
That Time I Got Reincarnated as a Slime Vol.1
But if you want the full picture — spin-offs, anime mapping, format advice, and tips for new readers — keep going.
Every Edition and Format Compared
Before you start buying, it helps to know what formats are actually out there so you can pick the one that works best for your budget and shelf space.
Standard Single Volumes
The main way to read That Time I Got Reincarnated as a Slime in English is through standard single volumes. These are the individual numbered books you’ll find at bookstores and online retailers. Each volume collects several chapters from the magazine installments into one book.
With 29 English volumes currently available, this is a long series in physical form. That’s a real shelf commitment — we’re talking about two feet of manga if you line them all up.
As of early 2026, omnibus editions and box sets are available alongside the standard single volumes. Kodansha has released at least three omnibus editions — Omnibus 1 (Vol. 1–3), Omnibus 2 (Vol. 4–6), and Omnibus 3 (Vol. 7–9) — plus Season 1 manga box sets covering the first arc. If you’re buying the full series, omnibus editions can be a more cost-effective option and take up less shelf space than buying individual volumes.
If you’re brand new to manga: these books read right-to-left, both page order and panel order. It feels strange for about five minutes, then becomes second nature. There’s usually a note on the back cover explaining this.
Digital Editions
Digital volumes are available on major platforms including Kindle, Kobo, and BookWalker. The content is identical to the physical release — same translation, same pages, same everything.
For a series this long, digital has some real practical advantages. You don’t need shelf space, you can read on your phone or tablet anywhere, and digital editions frequently show up at lower prices during seasonal sales on these platforms. If you’re budget-conscious and looking at 29+ volumes, digital is genuinely worth considering.
That said, physical volumes are widely stocked at major retailers and bookstores, so availability isn’t an issue either way.
A Note on the Light Novel
You’ll see That Time I Got Reincarnated as a Slime light novels sitting right next to the manga on bookstore shelves. A light novel is a type of Japanese prose fiction — think of a short novel with occasional illustrations. These are the original source material written by Fuse — the story the manga retells in comic form.
This is important: the light novel and the manga are different products. They tell the same story, but the light novel is prose fiction, while the manga is a full comic version. They are not interchangeable. You don’t need both to follow the story — pick whichever format you prefer.
The light novel is published in English by Yen Press (an American publisher specializing in Japanese fiction), while the manga comes from Kodansha. They have different volume numbering, different pacing, and the light novel is further ahead in the story than the manga. We’ll come back to that in the tips section.
| Feature | Main Manga | Light Novel |
|---|---|---|
| Format | Comics / graphic novel | Prose with illustrations |
| Story | Retells the light novel in comic form | Original source |
| English Volumes | 29 (as of Mar 2026) | Published by Yen Press, ahead of manga |
| Publisher (EN) | Kodansha | Yen Press |
| Best For | Visual readers, manga fans | Readers who want the full story fastest |
Full Manga Reading Order with Spin-Offs
Now let’s talk about all those spin-off manga you keep seeing. A spin-off is a separate manga series set in the same world, featuring some of the same characters, but telling its own story. There are several for this franchise, and they range from comedic everyday-life stories to world-building side content. Here’s how they fit into the bigger picture.
The Main Manga Comes First — Always
No matter how you structure your reading, the main That Time I Got Reincarnated as a Slime manga is the trunk of the tree. Every spin-off assumes you’re already familiar with Rimuru, Tempest, and the core cast. Read the main series first (or at least get several volumes in) before branching out.
Slime Diaries (Tensura Nikki)
The Slime Diaries: That Time I Got Reincarnated as a Slime is a slice-of-life comedy spin-off. “Slice-of-life” means low-stakes, everyday storytelling — no major battles or plot twists, just characters living their lives. “Tensura” is the commonly used fan abbreviation of the Japanese title, so you’ll see it a lot in online discussions. This spin-off follows Rimuru and the residents of Tempest in their everyday lives — festivals, cooking, goofing around, the kind of fun that the main series doesn’t always have room for.
This spin-off is charming and genuinely funny, but it’s pure side content. There’s no plot-critical information here. Think of it as a cozy bonus for when you’re already invested in these characters and want to hang out with them in a more relaxed setting.
When to read it: After you’ve read at least the first several volumes of the main manga (roughly through Volume 5), you’ll have enough context to enjoy Slime Diaries. You can read it alongside the main series from that point, or save it for after you’ve caught up.
The Slime Diaries: That Time I Got Reincarnated as a Slime, Vol. 1
Trinity in Tempest
Trinity in Tempest follows three young monster visitors — Phos (a fox clan girl), Stella (a dragon clan girl), and Nemu (a winged clan girl) — who travel to Tempest to observe and experience life in Rimuru’s nation firsthand. It’s a tour-and-discovery story told from outsiders’ perspectives, showing how the wider world perceives what Rimuru has built.
When to read it: This one works best after you’ve gotten through a chunk of the main manga — at least through Volume 7 — so you understand how Tempest functions as a nation and who the key figures are. It’s a standalone side story and completely optional.
The Ways of the Monster Nation
The Ways of the Monster Nation takes a wider view of the world, telling stories from the perspectives of various monsters across Rimuru’s growing nation. It’s great for fleshing out the setting and adds texture to the world, but again, it contains nothing you need for the main plot.
Note: This series went on hiatus in March 2021 and was officially cancelled in April 2024 due to the artist’s poor health and inability to resume serialization, and was never completed. If you pick it up, be aware that the story ends without a proper conclusion.
When to read it: Anytime after you’re familiar with the basics of Tempest and its inhabitants — around Volume 7 of the main manga is a good starting point. This one is the most supplemental of the spin-offs — pure flavor, though bear in mind you will encounter an unfinished story.
Other Short Spin-Offs
There are a handful of other short spin-offs and anthology chapters that have appeared over the years. These are purely optional and add small moments of character interaction or comedy. None contain plot-critical content. If you see them and you’re already a fan, go for it. If not, skip them without worry.
Recommended Spin-Off Insertion Points
Here’s a rough guide for when to slot spin-offs into your main manga reading:
| Main Manga Progress | Spin-Off You Can Start |
|---|---|
| After Volume 5 | Slime Diaries |
| After Volume 7 | Trinity in Tempest |
| After Volume 7 | The Ways of the Monster Nation |
| After Volume 5 | Other short spin-offs |
Remember: these are suggestions, not requirements. You can read every spin-off after finishing the main manga if you’d rather not interrupt your reading flow. That’s a perfectly good approach.
Anime Watch Order vs. Manga Reading Order
A lot of people come to the manga after watching the anime, so let’s talk about how the two line up.
The Anime Follows the Manga (Which Follows the Light Novel)
The That Time I Got Reincarnated as a Slime anime retells the same story as the manga, which itself retells the light novel. The chain goes: light novel → manga → anime. All three tell the same core story, with the anime being the most condensed and the light novel being the most detailed.
The anime has had multiple seasons, plus films and OVAs (standalone animated episodes released outside of the regular TV seasons, often on home video or streaming platforms). If you’ve watched the anime and want to continue in manga form, the key question is: where does each season end in the manga?
Picking Up the Manga After the Anime
The exact manga volume that corresponds to the end of each anime season can shift slightly depending on how much material each season covers. Rather than giving you a specific volume number that might be off by one, here’s the safest approach:
Start a volume or two before where you think the anime left off. Seriously. The manga includes details, scenes, and character moments that the anime condenses or skips entirely. You’ll get more out of the story by overlapping a bit rather than trying to pinpoint the exact chapter where the anime stopped.
If you’ve watched all available anime seasons and want to continue, check which storyline segment you ended on and find the corresponding manga volume. The Tensura Wiki (easily found via search) maintains detailed breakdowns of which anime episodes correspond to which manga chapters and volumes. Community discussion boards on Reddit (r/TenseiSlime) are also reliable for this kind of question — people ask it regularly and the answers are well-established.
Anime-Original Content
The franchise includes anime films and OVAs that have original storylines not found in the manga. These are generally designed to fit into the timeline without contradicting the main story, but they won’t appear in your manga reading order because they were created specifically for the anime.
If you encounter a movie or OVA while watching, just enjoy it as a standalone adventure — then continue with the manga in numbered order. You won’t miss anything critical.
The Slime Diaries spin-off also received its own short anime adaptation, which covers the same everyday-life content as the Slime Diaries manga.
Tips for New Readers Starting the Series
Just Start with Volume 1
No prerequisites. No required background reading. No “you need to watch the anime first.” Just grab Volume 1 of the main manga and go.
The first volume drops you right into the premise and the story builds naturally from there. Characters, the rules of how the fantasy world works, and the power system (how characters’ abilities function and grow) all get introduced at a comfortable pace.
The Pacing Gets Better
A heads-up: the early volumes spend a good amount of time on establishing the world, Rimuru’s abilities, and alliances. Some readers find Volumes 1–3 a bit slow compared to what comes later. Stick with it. The story ramps up significantly once the political and military conflicts start heating up, and all that early groundwork pays off when the stakes get higher.
Don’t Start with Spin-Offs
This might seem obvious, but it’s worth saying clearly: do not pick up Slime Diaries or Trinity in Tempest as your first Tensura manga. They assume you already know who Rimuru is, what Tempest is, and why any of it matters. Starting with a spin-off will leave you confused and spoiled on plot points from the main series.
Budget-Friendly Reading
Twenty-nine volumes (and counting) is a real investment. Here are some ways to manage the cost:
- Digital sales happen regularly on platforms like Kindle, Kobo, and BookWalker. Keep an eye out during major seasonal sales and you can pick up volumes well below their list price.
- Library borrowing is a genuinely great option. Many public library systems stock popular manga series, including this one. If your local library doesn’t have it, check whether they offer interlibrary loans (requesting books from other libraries in the system) or digital manga through apps like Libby or hoopla.
- Buy in batches rather than all at once. There’s no rush. The series isn’t going anywhere.
- Wishlist and alert features on platforms like BookWalker and Kindle let you mark volumes you want and get notified about price drops, so you don’t have to check manually.
The Light Novel Goes Further
If you catch up to Volume 29 of the manga and want to know what happens next, the light novel is your answer. Published in English by Yen Press, the light novel is further ahead in the story than the manga. It’s a different reading experience (prose instead of comics), but the story is the same, just more detailed. Many fans switch to the light novel after catching up on the manga to get ahead.
Where to Start Today
Let’s wrap this up with a clear game plan.
Step 1: Grab Volume 1 of the main That Time I Got Reincarnated as a Slime manga in whatever format you prefer — physical or digital.
Step 2: Read straight through in numbered order. Volume 1, Volume 2, Volume 3, all the way to Volume 29. That’s the whole core reading order.
Step 3: Skip the spin-offs on your first read-through. Come back for Slime Diaries and Trinity in Tempest after you’re invested in the world and characters. They’re fun, but they’re dessert, not the main course.
Step 4: If you catch up to the English manga release and want more, the light novel continues the story further ahead.
Digital single volumes are the most accessible and cost-effective entry point for a series this long. But if you love having physical manga on your shelf, the standard volumes are widely available.
The series is ongoing — new English volumes are still releasing regularly, with Japan a few volumes ahead. You’ll eventually catch up to the English release, but that’s a good problem to have. It means you’ve got a long, satisfying read ahead of you before you ever have to wait for the next volume.
Rimuru’s story is one of the biggest isekai manga running today, and it earned that spot. Grab Volume 1 and see for yourself.