Leviathan is a 3 volume sci-fi horror manga series. It is a beautifully drawn page turning sci-fi survival horror manga that takes place on a massive, abandoned spaceship, known as the Leviathan. The ship was said to have just vanished on its way back to earth, but it has been drifting somewhere deep in space. The ship is then discovered by a group of looters who break into it looking for anything they can grab and stumble across something very disturbing. The notebook of a middle-schooler named Kazuma, who documented the school trip along with the horrors that ensued.
Journal of Horrors
Through Kazuma’s entries, we slowly piece together what really happened to all the passengers. What was supposed to be an innocent school trip turns into a nightmare when the ship is struck, causing major damage and becomes stranded with no hope of rescue. Oxygen is running out, panic sets in, and soon the children find out that there’s only one way to survive: a cryo pod that can hold just one person.
From there, the oxygen clock is ticking and things spiral out of control fast. The adults don’t make it out alive, friendships are divided into social classes, but when that doesn’t work, all the classmates turn on each other as the desperation for survival takes over. Kazuma’s diary captures the slow mental breakdown of everyone around him in a way that’s chilling without ever letting up. The creepiest part is as the looters keep reading, they come to a terrifying realization that someone might still be alive somewhere inside the Leviathan. Shiro Kuroi gives the reader a story that has many twists and turns. Just when you think you know where the story is going the following volume throws its reader for a loop.
What I Love
First and foremost, the art, because in any and all sci-fi horror, atmosphere is crucial. Kuroi’s style is strikingly precise, very detailed and beautiful, to the point where the reader can linger on every panel and uncover something new each time they look. One of my favorite examples is the Looters’ face shields: the reflections etched into the glass are haunting, offering distorted glimpses of the devastation around them and subtly revealing what the characters are seeing as they sift through the wreckage. These stunning visual choices heighten the tension without the use of dialogue.
Kuroi’s line work is masterful, and his use of varied crosshatching patterns bring an eerie interplay of light and shadow that gives the world weight, depth, and a constant sense of unease. Every line feels deliberate. As Manga is restricted to black ink on white paper, artists can’t rely on color to amplify emotion, this level of precision is crucial and Kuroi excels at it. His artwork carries the horror just as much as the narrative, making this manga not just unsettling to read, but mesmerizing to look at, making him a huge breakout manga star.
Relentlessly Suffocating Narrative
The story itself is tightly executed and effortlessly engaging. It pulls the reader in from the start and rarely loosens its grip, you could easily burn through the entire series in a single day. The pacing is steady and each chapter pushes you forward with a growing sense of dread.
At its core, the series explores an unsettling idea: children harming other children in order to survive. It’s a concept that may make some readers uncomfortable, as children are often viewed as purely innocent beings meant to be protected, not capable of violence against one another. But how true is that assumption, really?
Kuroi approaches this theme with a realism that feels disturbingly grounded. When a human life is genuinely at risk, age becomes irrelevant. Survival instinct takes over. The desire to live and to keep breathing no matter the cost is universal. Leviathan doesn’t shy away from this truth; instead, it examines it from every angle, forcing the reader to confront what survival looks like when morality is stripped down to its bare bones.
With that, let’s dig into each volume. (This next part will contain spoilers so please stop here, and go check out this series.)
Volume 1 (Oct 2024) – English Print
Three looters break into an abandoned and wrecked spaceship called The Leviathan. Deep inside the ruins, they uncover a notebook belonging to Kazuma. As one of the Looters reads it aloud, the grim truth emerges, the ship filled with passengers had vanished midway between Proxima and Earth, its fate sealed long before rescue ever came.The notebook drags the reader back to the moment everything fell apart.
At the beginning of this school trip, Teacher Senda breaks up a bullying incident, urging Kuki to defend himself. Not long after that an explosion ripped through the ship. Teachers and children are forced into the main square. A six-legged robot and the head teacher, Senri, attempt to reach the bridge, only to find the emergency hatches sealed.
While sent to retrieve medical supplies, Kazuma and Futaba overhear a horrifying secret. The ship is cut off from the outside world, oxygen will run out in fifty hours, and there is only one cryosleep capsule capable of saving a single life. The knowledge seals their fates. Later Senri attacks Futaba to silence her, as he knows she heard the robots reportings, she kills him in self-defense.
Kazuma tries to warn the remaining teachers, but no one believes him. The robot denies everything. Futaba lies about what was overheard. Soon after, Senri is found dead, and suspicion begins to plague the group dynamic.
As the students spread rumors of sabotage and government enemies among themselves, the trust collapses completely. Then Kazuma’s notebook ends up in the wrong hands causing even more disarray. One student is pushed from a railing, another is murdered trying to save him. By the time an emergency meeting is called, fear has fully taken control.
When Kazuma finally reveals the oxygen shortage and the single chance for survival, the group falls apart and turns on one another. The children flee, arming themselves while all order is shattered, innocence gone, and only individual survival matters.
Volume 2 (Jan 2025) – English Print
As the violence escalates among the students, San teams up with Kazuma. Elsewhere on the ship, Kyo takes revenge on his tormentors, wounding one and using him as bait. Kyo later confronts Yotsu and his friend, and all three die in the violent fight.
Kazuma and San meet Yo, who warns that the ship’s air supply is failing. They return to the dining hall, now controlled by armed students. Class divisions have hardened: the wealthy “Uptowners” dominate the space and view the working-class “Locals” with hostility.
During an attack, Yo organizes a defense but chaos erupts when an “Locals” intruder kills a student before being shot. Yo is falsely accused of betrayal, forcing him to flee. Soon after the armed “Locals” get past the barricade easily overwhelming the “Uptowners”.
Kazuma and San escape through the ventilation shaft. Roku, leader of the stronger students, turns on his own group and survives. Yo joins him, declaring his intent to kill Kazuma. Overhearing this, Kazuma confronts Roku and leaves the injured San behind, and ultimately kills Roku using a forklift after finding an oxygen cylinder.
In the present day, wreck raiders defeat the six-legged robot described in the diary using explosives and gunfire.
Volume 3 (Sep 2025) – English Print
After the battle, the Leviathan begins to collapse. Wreck looters recover the ship’s data storage and review the camera footage and what they see contradicts the found notebook. Futaba appears missing from footage. The truth is that Kazuma killed the Senri, then strangled Fitaba and hid her body. His guilt caused him to imagine she was still alive.
As the hallucinations continue to distorte Kazuma’s perception he later comes to believe Futaba trying to attack him and he “stabs” her only to realize he had stabbed his own reflection. When he finds the injured San, San refuses to fight him or anyone. As the oxygen clock is nearing its end, San collapses, and Kazuma carries him to a cryo pod, wanting to keep whatever humanity he has in him. Kazuma chooses to save San.
The looters eventually find the pod and Kazuma’s body. When they open it, San awakens and recognizes his old classmate Yo Yahata, one of the Looters.
Yo reveals the truth to San and the two other looters.
The Leviathan was part of a government experiment to observe students under hopeless and violent conditions. He escaped during the chaos, but was captured soon after. Later Yo memorized the ship’s coordinates.Once the government fell and all records were destroyed, Yo had to track down the director of the Leviathan Project, Dr. Manjome, who Yo had killed before joining the Looters to find the lone survivor.
Yo Yahata, San Mikami, and the others leave the wreck through a breach in the hull. From the Looter’s ship, the only two survivors look back at the Leviathan drifting in silence.
Each volume does contain bonus stuff at the end of the Manga. Vol 1 has character snippets, Vol 2 has sketches by the writer that weren’t used in the series and Vol 3 has an interview with Shiro Kuroi. I really love when Manga/Comics and Graphic Novel creators share these behind the scene stuff with their readers.
I highly recommend this series for anyone who enjoys Sci-fi Horror, exploring the darker parts of the human experience, government conspiracies and knows exactly what great Manga art should look like. This series is a really fun read and visually stunning.