Black Cat Review: The Assassin Who Learned to Live Freely

I read Black Cat in my early twenties, during a stretch where I felt like I was just doing what was expected of me and nothing more. I picked it up because the cover looked cool — a guy with a gun and a cat tattoo, that early-2000s Shonen Jump look I grew up with. I figured it would be a fun action series and nothing else. But the part that stayed with me wasn't the gunfights. It was a single line about milk, and a girl who told a contract killer that he was allowed to want things for himself.

That sounds small. With this manga, it isn't.

Quick Take

• A gunslinger assassin for a secret world-controlling organization walks away from everything after a sweeper named Saya shows him that his life is a choice he can unmake — then he chases the man who killed her
• Clean, fast, stylish action from Kentaro Yabuki (who later drew To Love Ru), but more focused and serious than that comparison suggests
• 20 volumes, complete; rated T (Teen) for gun violence and a dark backstory, but nothing graphic

Story Overview

Chronos is a secret organization that quietly controls a third of the world's economy, and its sharpest tools are the Numbers — thirteen elite operatives. Train Heartnet is Number XIII, the assassin called "Black Cat," with a numeral tattooed on his collarbone and a custom gun named Hades. He's frighteningly efficient and completely hollow. Killing is just the thing he does.

The turning point isn't a battle. It's Saya Minatsuki, a freelance sweeper (bounty hunter) who keeps crossing paths with Train on rooftops. She steals his milk, sings to herself, and talks to him like he's a person rather than a weapon. Slowly she gets him thinking about the idea that he could choose his own life instead of taking orders. Train starts disobeying Chronos. Then Creed Diskenth — a fellow operative obsessed with Train, who believes Saya has "bewitched" him and made him weak — murders her. She dies in Train's arms during a fireworks show.

After that, Train abandons Chronos and becomes a sweeper himself. He partners with the experienced, level-headed Sven Vollfied, and together they free Eve, a child built as a nanomachine bio-weapon. The back half follows Train hunting Creed, who has raised an army called the Apostles of the Stars to tear Chronos down. It builds to a final clash on Creed's island, and the ending hinges on a choice Train makes that I'll get to below.

Characters

Train Heartnet — The whole manga is the distance between who Train was and who he becomes. He starts as Number XIII, a killer with no wants of his own, and ends as a sweeper who decides who he protects. What I like is that the change isn't instant or clean — Saya cracks him open, her death nearly turns him back into a weapon of pure revenge, and the ending is him refusing that pull.

Saya Minatsuki — A sweeper who meets Train on the rooftops, loves milk after singing, and treats him as an equal long before he's earned it. She's the one who plants the idea that he can live freely. She dies relatively early, but her presence shapes everything Train does for the rest of the series.

Sven Vollfied — The seasoned sweeper who becomes Train's partner. He's the steady, almost paternal center of the trio, and his protectiveness toward Eve is where a lot of the manga's warmth lives.

Creed Diskenth — The antagonist, a former Chronos operative whose admiration for Train curdles into obsession. He kills Saya specifically because he thinks she's making Train soft, then builds the Apostles of the Stars to remake the world. His fixation is the engine of the whole second half.

What I Love About It

The thing I love is the milk. When Saya first shows up, she's stealing the milk Train leaves out for stray cats — and Saya herself loves a glass of milk after she sings. It's such a tiny, human detail to hang on a story about a contract killer. Train has no friends, no wants, no life outside Chronos, and the first crack in all of that is a girl drinking his cats' milk on a rooftop and not being afraid of him.

What got me is how Yabuki uses that smallness on purpose. Saya never lectures Train about morality or gives him a big speech about right and wrong. She just lives openly — singing, drinking milk, taking sweeper jobs because she wants to, not because anyone orders her to — and lets Train notice that a person is allowed to do that. Watching the most dangerous assassin in the world slowly realize he's permitted to want something as ordinary as a quiet evening, because a girl who likes milk made it look possible, hit me harder than any of the gunfights. That's the heart of the series for me, and it's why the rest of the revenge plot carries weight at all.

Memorable Scene ⚠️ Spoiler Warning

Saya's death is the scene I can't shake. Creed comes for her, declaring he'll kill her to break the "spell" she's put on Train. Saya fights back — she lands a hit on him — but she's distracted protecting a group of kids nearby, and Creed uses that opening to stab her. Train reaches her, holds her, and tells her to hold on, that he'll get a doctor.

What destroys me is her response. She smiles up at him and says she just wanted her ramen — a callback to a promise Train had made her about a fireworks show and a bowl of ramen. Then, with the fireworks reflecting in her eyes, she dies in his arms. The contrast is brutal: the sky exploding with light overhead, and this quiet, almost casual line about ramen as her last words. It reframes the entire series. Everything Train does afterward — leaving Chronos, hunting Creed, and finally the choice he makes at the very end not to become a killer again — comes back to that rooftop girl and her glass of milk.

Pros & Cons

Pros

• 20 volumes, complete, with a genuinely satisfying conclusion and no padding
• Train's arc from hollow assassin to someone who chooses his own life is cleanly executed
• Yabuki's art is stylish and consistent; the gun action is dynamic and easy to follow
• The Train/Sven/Eve found-family trio gives the back half real warmth

Cons

• The story depth is shallower than the genre's heavy hitters — it's a clean ride, not a deep one
• The Apostles of the Stars are a more interesting threat as a concept than as individual villains
• It leans hard on early-2000s shonen conventions that feel a little dated now, and that nostalgia-versus-staleness line is personal — this one won't work for everyone.

Is Black Cat Worth Reading?

Yes, if you want a complete, stylish action series that knows exactly how long it should be and ends well. It's not the deepest manga on the shelf, but the emotional spine — an assassin learning he's allowed to live, anchored by a girl, a rooftop, and a glass of milk — is stronger than the cool-gunslinger cover lets on. If you want a finished story you can read in a couple of sittings, it delivers.

Where to Buy

Read the first volume. If it doesn't hook you, put it down. It'll hook you.

Start with Volume 1 →

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