Seinen refers to a demographic of anime and manga primarily targeted at young adult men. While shonen is geared more toward kids and features themes of friendship and hard work, seinen series cover more complex topics like revenge and political commentary.

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Seinen anime isn't exactly known for being lighthearted. Some series, like Kaguya-Sama: Love Is War or Miss Kobayashi's Dragon Maid, aren't nearly as heavy as other titles in the genre. However, they still have a more mature sense of humor that wouldn't be appropriate in shonen or shojo. Some seinen anime, however, fit the genre's trademark dark, violent, and gritty stereotypes.

10 Vinland Saga Is A Violent Series Where Revenge Is At The Forefront Of Everything

Thorfinn ready for battle in Vinland Saga.

Vinland Saga follows Thorfinn on his warpath toward revenge for his father's murder. Askeladd, the man who killed him, is a prolific anti-hero who only cares about advancing his power. He's charming to the general public, but his enemies know he's a violent, manipulative, and ruthless monster.

At its core, Vinland Saga is a series about revenge. It's at the forefront of everything. Though Vinland Saga isn't as dark as other gritty seinen hits like Berserk, its realistic characters and real-world historical references don't romanticize the time it's representing. Vikings were brutal, and Vinland Saga perfectly depicts it.

9 Erased Is A Time-Travel Murder Mystery That Doesn't Deserve The Hate

Kayo Hinazuki and Satoru Fujinuma from the Erased anime

Erased receives lots of flack and mockery on social media because of its ending, and some argue that it cheapened the plot. Still, there's no denying Erased's popularity and unique premise that sets it apart from the rest.

Erased follows Satoru Fujinuma, a manga author who struggles to make ends meet and whose life is suddenly turned upside down when he's framed as a murderer. Satoru has the power to go back in time and prevent tragedies from occurring, so he uses it to find out who the real killer is.

8 Parasyte Is A Twisted Sci-Fi Series That Challenges The Human Condition

Parasyte's Shinichi talking to Migi.

Parasyte quickly became one of the most critically-acclaimed seinen series after its 2014 premiere. The series follows Shinichi, an average high schooler whose life is turned upside down when an extraterrestrial parasite tries to possess him. The parasite fails and ends up taking residency in Shinichi's right hand.

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Shinichi aptly names his new companion "Migi." The bizarre duo takes on the world as other alien parasites invade the earth and try taking over. Parasyte challenges and deconstructs the human condition, making viewers question if they're so different from the monsters they've grown accustomed to fearing.

7 Monster Is About A Neurosurgeon Whose Life Is Upended By A Troublesome Patient

Tenma holding a gun in Monster

Monster's 2004 anime adaptation was a smash-hit after viewers became immersed in the chaotic world of Kenzo Tenma. He's a neurosurgeon whose life turns for the worse after he decides to save a young boy's life over the mayor. Tenma didn't know then, but the young boy he saved would grow up to become a serial killer.

Monster is full of complex characters and serves as a character study. Tenma faced a difficult choice, but now everything is a constant reminder that actions have consequences. He chose to save a young boy's life, but that kid grew up to become a monster. Tenma saved his life, but he needs to be the one to end Johan Liebert's reign of terror.

6 Akira Is A Cyberpunk Film That Exposes The Harsh Realities Of War

The center of Neo Tokyo in Akira.

Akira is one of the most famous films to ever come out of Japan. After its 1988 premiere, the film grossed roughly $49 million at the box office and received an endless stream of critical acclaim, consequentially busting the door down and forcing anime into the Western mainstream.

Akira is a dystopian cyberpunk movie that depicts the harsh realities of war. Set in 2019, Akira depicts the third world war and is set in Neo-Tokyo, a reimagined version of the city after it was destroyed. Although Akira has a cool aesthetic, it gets the viewer thinking about the meaning of constant warfare and forces them to evaluate its long-lasting effects.

5 Hellsing Is A Gory Series About Vampires

Alucard the heroic vampire grinning in Hellsing.

Hellsing proves that evil never dies. The series stars Alucard, one of anime's most prolific anti-heroes. The titular Hellsing tracks down and eliminates dangerous supernatural beings. Still, they had their work cut out for them when they were tasked with eliminating monsters terrorizing the village of Cheddar.

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The only one who could get the job done was Alucard. Many criticize Hellsing for being too violent for its own good and claim that its heavy reliance on shock value disservices the series, but its trademark blood and guts are part of its charm.

4 Berserk Is A Distressing Series That Isn't For The Fainthearted

Guts, the main character of Berserk, holding a sword behind his head.

There's no bright side in Berserk. It's one of the grittiest seinen series of all time, but it's critically acclaimed for not over-relying on gorier visuals and edgelord sentiments to drive the plot. Instead, viewers praise Berserk's troubled anti-hero of a protagonist, Guts.

Viewers also fell in love with Griffith, who is widely regarded as one of anime's most well-written villains. Nihilism is at the forefront of Berserk, making viewers question reality as they watch Guts continue to fight on, even though it's explicitly implied that his life will never improve.

3 Elfen Lied's Constant Gorefests Caused Widespread Controversy

Lucy from Elfen Lied with blood spatter on her hands and to the left.

Elfen Lied is a gorefest that's been banned in several countries. Still, it's an influential series that inspires many others, including western hits like Stranger Things. Elfen Lied follows the Diclonii, a mutant species whose innate desire is to eradicate humankind and usher in a new world where they can thrive. However, the Diclonii are mutant humans spawned from people infected by an invasive Diclonius.

Elfen Lied covers heavy themes of prejudice, jealousy, and what it means to be human. Unfortunately, the series receives lots of flack for its perceived overreliance on blood and guts to drive the plot.

2 Ken Kaneki's Life Is A Tragedy In Tokyo Ghoul

Tokyo Ghoul's Ken Kaneki in the anime versus in the manga.

Disregarding Tokyo Ghoul as fodder for edgelords is the biggest mistake that any fan of dark fiction could possibly make. Though Ken Kaneki has become someone of a meme with emo kids and male manipulators alike using him as their profile picture on social media, Tokyo Ghoul is nothing short of a masterpiece.

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Written by Sui Ishida, Tokyo Ghoul follows Ken Kaneki after a bizarre accident turns him into a half-human and half-man-eating ghoul. He's too monstrous for humanity, but too human to fit in with other ghouls. Throughout Tokyo Ghoul, Kaneki's humanity is in a brutal game of tug-of-war against his ghoulishness.

1 Code Geass' Protagonist Started Out As Hero, But He Quickly Succumbed To Villainy

Lelouch devises a plan in Code Geass: Lelouch Of The Resurrection.

Code Geass is fast-paced and action-packed like a typical shonen anime, but its protagonist and heavy social commentary solidify it as a thrilling seinen series. Lelouch started out with the heroic goal of avenging his family and dismantling Britannia's tyrannical iron fist.

​​​​​​​Unfortunately, Lelouch was corrupted with power after discovering the capabilities of mecha abilities and the titular Geass. Lelouch became a complicated anti-hero. Code Geass shows what happens to people during times of neverending warfare. It also recognizes that the human mind is more feeble than anybody would admit.

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