If you’re looking for more mature anime or new to this genre, here are some of the best series worth checking out. Anything from dark, heavy stories to more lighthearted ones.
1An elite neurosurgeon becomes haunted after saving a young boy who later turns into a dangerous killer, leading him to pursue the truth. A tense psychological thriller seinen focused on morality, guilt, and the consequences of one's decision.
2Vinland Saga starts with brutal Viking warfare but grows into something more reflective, following characters shaped by revenge, loss, and changing ideas about what it means to live and fight.
3In a future where a system determines who’s likely to become a criminal, Psycho-Pass follows the enforcers sent to eliminate threats before they act. A cyberpunk thriller about justice, control, and whether a perfect system can ever really be fair.
4A former soldier and an Ainu girl search for stolen gold across Hokkaido while competing with other factions doing the same. Golden Kamuy mixes historical detail, survival adventure, and offbeat comedy into a fun chaotic treasure hunt.
5A salaryman falls in with a mercenary crew in a lawless Southeast Asian port city and gets dragged into the criminal underworld. A fast, violent action series where survival matters more than morality and nobody really comes out clean.
6A man infiltrates the mafia family that killed his family in Prohibition-era America, planning revenge from inside their ranks. A slow, tense crime drama about deception, loyalty, and how revenge keeps the cycle of violence going.
7A pair of handymen take on jobs in a crime-ridden city where gangs, corrupt officials, and the police all operate in uneasy balance. A seinen crime drama focused on underground work, organised crime, and the struggles of people living on the margins of a violent society.
8A high school student shares his body with an alien parasite, while others of its kind quietly infiltrate human society. A psychological sci-fi horror series that stands out in seinen for its mature themes, moral dilemmas, and unsettling questions about what it means to be human.
9A man with a reptile head and no memory hunts sorcerers in a filthy, chaotic city where magic is part of everyday violence. A gritty, absurd seinen that mixes brutal gore with strange humor and a completely unhinged world that somehow still has rules.
10A condemned ninja is sent with other death row criminals to a mysterious island in search of the elixir of immortality. Hell’s Paradise is a brutal survival story where beauty and horror collide, filled with intense action, shifting alliances, and nightmarish creatures lurking in the island’s depths.
11A wandering and timid ronin gets pulled into a kidnapping gang in Edo and finds himself stuck in their uneasy world. A slow character driven seinen focused on fragile relationships, quiet tension, and adults making compromised choices to get by.