Whereas shonen anime is primarily aimed at younger boys, seinen anime usually refers to series geared towards a slightly older audience, with complex characters and more mature humor than its counterpart. The amazing comedy releasing this year including Kaguya-same: Love is War provides a perfect example, with well-written central characters bringing out a more subtle kind of humor.
Similarly, great characters are at the heart of what makes all seinen anime work. With One Punch Man's Saitama and Berserk's Guts great demonstrations of the kind of iconic protagonists the genre can produce, anime fans on Ranker voted on which of these seinen characters are one step above the rest.
Note: Ranker lists are live and continue to accrue votes, so some rankings may have changed after this publishing.
Rei Kiriyama (March Comes In Like A Lion)
Living up to the potential of the seinen genre, March Comes In Like a Lion is an intimate show focused on a young Shogi prodigy who struggles with the pressures that come with the highly competitive scene of the Japanese board game. Living alone and isolated, the show paints a strikingly resonant picture of a young man still suffering from the trauma of his youth.
Although the show promises to show Rei opening up to others and learning to deal with his problems in more healthy ways, it doesn't offer any easy answers as a show aimed at a younger audience might. Instead, his realistic character arc that manages to be inspiring without being preachy hit home for fans of Ranker.
Saichi Sugimoto (Golden Kamuy)
Seinen anime tends to bring with it older main characters, cynical people who have been jaded by a harsh world, and the aggressive, scarred Saichi Sugimoto is a great example of this. An ex-soldier renowned for his feats in battle, Sugimoto is now reduced to searching for treasure in early 1900s Hokkaido.
Whilst this may make him seem like nothing more than an opportunist, Sugimoto's reasons for seeking fortune are incredibly pure and speak a lot for the nuance and hidden kindness of the rough protagonist. Whilst the show also gives plenty of opportunities to see the man in satisfyingly violent action, it is this nuance that makes him so popular.
Ginko (Mushishi)
One of the best anime with an adult protagonist, Mushishi uses Ginko as a means to explore the unique world and endlessly fascinating stories of the anime. In the show, Ginko is a Mushishi tasked with uncovering the mysteries of a life form fundamental to our world known as Mushi.
It's almost a surprise how popular Ginko is, as he's as enigmatic as the show, remaining calm and adapting to the different situations that every episode puts him in. Ginko makes a great contrast from the impulsiveness that defines a lot of shonen and even seinen main characters, almost settling into the background of a show all about telling engrossing stories.
Alucard (Hellsing)
Perhaps the only thing more intimidating than a vampire is a vampire with a gun so it's lucky Alucard is the protagonist of Hellsing rather than the antagonist. Working for an organization that's all about taking on supernatural threats, Alucard employs his wide range of powerful abilities to tear apart his brethren of the night in some of the best anime action around.
Whilst shonen anime isn't a stranger to antiheroes, the violent protagonist of Hellsing goes beyond that. There's a depth to Alucard that's slowly uncovered as the series continues that made fans genuinely sympathetic for the blood-eyed vampire. Alucard is a big part of what makes the show so compelling.
Shinichi Izumi (Parasyte: The Maxim)
Great characters are formed through adversity and this is certainly the case with Shinichi Izumi, as the show begins with him creatively preventing an alien parasite from taking over his body. Instead, the creature settles in his arm as Shinichi is forced to wrestle no longer being entirely human.
Unfortunately for the protagonist of Parasyte: The Maxim, that's only the beginning of his troubles as the aliens have already begun their invasion of Earth. Seeing Shinichi rise despite his struggles endeared him to a lot of fans so it's no surprise that he's a popular choice.
Kenzo Tenma (Monster)
There aren't many shows that go as far as Monster in examining issues of moral complexity and Kenzo Tenma is the perfect protagonist for this. An elite neurosurgeon who loses everything after choosing to operate on an orphan despite being told to operate on an important client instead, Tenma is surprised to find his position restored after some mysterious deaths at the hospital.
As it turns out, the titular monster is the one he unleashed by saving a child that would go on to become a killer. Tenma sees it as his duty to make amends for his choice, and it is this drive that forms the heart of the show. Monster is a quintessential seinen anime from the mid-2000s and it manages to remain popular with fans on Ranker.
Thorfinn (Vinland Saga)
One of the best seinen anime ever made, Vinland Saga is a Viking epic that explores heavy themes of revenge and the true impact of war. Thorfinn is the center of its bloody revenge plot after his father is killed in an underhanded surprise attack, and his skill in combat leads to some violence that could only feature in a seinen anime.
However, as the story unfolds, more layers to the story and the character emerge which made him instantly more relatable. As Thorfinn struggles to be self-reliant and complete his vengeance in a violent and unforgiving world, he begins to learn the importance of focusing on the future rather than looking single-mindedly at the past.
Saitama (One-Punch Man)
There simply isn't another protagonist quite like Saitama in anime. A man who wanted to be a hero so badly that he trained too hard and found he could beat every villain easily, making heroism boring, is a hilarious concept but also provides enough of an interesting background to a character that's genuinely interesting to follow.
One-Punch Man is a show all about his struggle to find meaning in life since the only thing he lived for can't bring him any joy. Whilst it makes fun of some tropes that are very prominent in shonen anime, Saitama's story of existential crisis could only be found in seinen anime so it's no surprise that seinen anime fans appreciate him.
Ken Kaneki (Tokyo Ghoul)
Tokyo Ghoul is a uniquely dark series about terrifying ghouls that can disguise themselves as humans whilst killing and eating them. Perhaps in a typical series, the protagonist would be someone who hunts down these creatures but unfortunately for Ken Kaneki, a reserved college student, he is destined to the painful fate of becoming a hybrid caught somewhere between human and ghoul.
Ken Kaneki is as complex as all the best seinen protagonists, desperately trying to cling to his humanity whilst being forced to confront the trauma that he's repressed for a long time. He isn't the most likable seinen protagonist but, for fans, he's still definitely one of the most fascinating to watch.
Guts (Berserk)
In the violent and uncompromising world of Berserk where sticking to values like honor can get you killed very fast, Guts is an appropriately dirty fighter as well as an accomplished swordsman. A mercenary who has been through a lot before being made to join the Band of the Hawk, Guts is the gritty emblem of all seinen protagonists.
Wielding a huge broadsword and a rough attitude, Guts perseveres through whatever is thrown at him. Guts' inner strength reflects his combat ability and he's not a man to back down from a fight. Despite some amazing seinen shows getting made, Guts is still the king of the genre as far as fans are concerned.