The seinen demographic for anime and manga is typically seen as more mature, usually aimed at young adult men. As such, seinen anime's themes, characters, and stories tend to reflect a more mature tone. That being said, one doesn't have to be in their adulthood in order to watch or enjoy seinen titles, as some actually share similarities with titles aimed at younger demographics.
While there are many great seinen titles to choose from, some are easier to watch than others. This doesn't necessarily mean that these titles are bad, but they can be frustrating to watch at times for a number of reasons.
10 Himouto! Umaru-Chan Has An Annoying Protagonist & One Repetitive Joke
Himouto! Umaru-Chan features the titular Umaru Doma, a girl who's seen as absolutely perfect by everyone at school. When she's home, though, she devolves into a spoiled and childish couch potato who drives her brother up the wall. While this series is not without its moments, what makes it hard to watch is actually Umaru herself.
Across two seasons, Umaru is just a complete brat who gets and does whatever she wants without any kind of consequence. All the jokes are also centered around her and her lazy antics, making it a very one-note and repetitive series.
9 Yamada's First Time: B-Gata H-Kei Is Mostly About Gaslighting One Poor Guy
Yamada is at the top of the social food chain at school. She's seen as flawless by everyone, and she's got only one goal in mind: being intimate with one hundred guys before she graduates. Despite her plans, she has no experience and has decided to make her first time the average and unassuming Kosuda, but it seems like just about everything gets in her way in doing that.
Yamada's First Time: B-Gata H-Kei's premise is rather risqué, though its flaws come from how tiresome Yamada's attempts to fulfill her goal are. It's also frustrating how she essentially gaslights poor Kosuda throughout the entire series, making her a rather unlikable protagonist to follow.
8 Fanservice Makes The Qwaser Of Stigmata Impossible To Take Seriously
Life takes a drastic turn for Mafuyu Oribe and Tomo Yamanobe as they end up in the middle of a power struggle between beings called "Qwasers" who can control elements, particularly the Adepts and an exile known as Alexander "Sasha" Nikolaevich Hell. There's just one catch: to draw out the Qwaser's power, they need "soma," which comes from a woman's breast.
With all that in mind, it becomes clear just what kind of show The Qwaser Of Stigmata is. While it tries hard to have a mature action-oriented story, the sheer level of fanservice ends up derailing it and makes it impossible to take the anime seriously.
7 Record Of Ragnarok Has An Interesting Concept, But It's Horribly Executed
Humanity has been judged by the gods as being unworthy of their continued existence, but they have one last chance to prove themselves in the tournament of Ragnarok. Thirteen of humankind's greatest will do battle with thirteen of the most powerful gods and only the strongest will survive. There's no doubt that Record Of Ragnarok's intense "man vs. god" action premise is interesting.
Unfortunately, Record of Ragnarok falls flat is its execution. Despite a prolific cast across time and mythology, the characterization is rather poor. While the anime tries its hardest to go for the potential of over-the-top spectacle, lackluster animation holds it back from really landing a decisive blow. For an anime all about fighting, that's not a good thing.
6 Kill Me Baby Has An Extremely Annoying Opening
Kill Me Baby stars two high school girls — the average Yasuna and the assassin Sonya who has some intense killer instincts when taken by surprise. Yasuna and Sonya go through their day-to-day lives, often having the most average day end with some violent and lethal results. Despite its cute and childish appearance, Kill Me Baby is a seinen that's all about its comedy, to mixed results.
Kill Me Baby has rapid-fire gags that could be seen as monotonous. Its most frustrating aspect, though, is probably the opening theme. Being both annoying and pretty tone-deaf at the same time could've been intentional, but all it does is create a turn-off for watching it.
5 Berserk Has Had A Very Tumultuous History
The story of the Black Swordsman, Guts, is full of death, demons, and revenge. Betrayed by someone he trusted and now hounded by monsters, Guts travels the world with a massive sword and equally massive strength, unable to rest until he has his retribution. Berserk is an iconic dark fantasy that's not for the faint of heart, there's no doubt about that.
Filled to the brim with action, dread, and a gritty atmosphere, Berserk is a classic. However, its tumultuous history has spread it out from one anime, several movies, and a poorly animated follow-up season, making it a little harder to follow for anime-only viewers.
4 There Are Basically No Likable Characters In Scum's Wish
Hanabi Yasuraoka and Mugi Awaya are what many in their school would consider a picture-perfect couple, but in truth, their relationship for convenience. Both Hanabi and Mugi are in love with a teacher at the school and know that they can't be with either of them. To fill that void, they decided to date.
Scum's Wish is an unorthodox kind of romance story, one that features all of its major players using each other for one reason or another whether it be romantic longing or physical longing. This makes it pretty hard to root for anyone in this anime, as they're all pretty unlikable for the things they do. At least the title is upfront about it, though.
3 Terra Formars Is Ruined By Its Censorship
In the distant future, Earth is being ravaged by an awful disease that has claimed the lives of many and the only hope for a cure might just be found on Mars. However, Mars is not the barren wasteland it once was, as cockroaches sent to the planet have mutated and now infest Mars. With few other options, a team is sent to Mars and forced to survive its new hostile inhabitants.
Terra Formars is not a series for the squeamish, as it's remembered less for the quality of its story and more for its sheer amount of violence and gore. Unfortunately, heavy and obnoxious censorship of that violence ruined even that, making it almost impossible to avoid being distracted.
2 Pretty Much Everything About Ex-Arm Makes It Hard To Watch
There are many anime titles that become infamous for one reason or another, but none as quickly or for as many reasons as Ex-Arm. This Crunchyroll Original series centers around a police force with a high-school-student-turned-AI joining an android girl and her human partner as they fight to stop anyone from misusing powerful weapons called "EX-ARMs" for their own gain.
Full of uninteresting characters, laughably horrible CGI animation, and some out-there plot twists, just about everything in Ex-Arm is done poorly. These flaws make it a failure of an adaptation and next to impossible to watch all the way through.
1 Tokyo Ghoul's Enjoyment Is Hampered By All The Times It Fell Flat
After barely surviving an assault from a flesh-eating ghoul, Ken Kaneki ends up half-ghoul himself and must learn to adapt with his new evolving body. As Kaneki is thrown into the conflict between ghouls and the government who hunt them like animals, his humanity becomes ever more distant.
In its early days, Tokyo Ghoul made a big splash for its heavy action/thriller atmosphere and its morose themes, such as loss of innocence and fear evolution. However, the longer the series continued, the more its flaws stood out. The enjoyment of watching Tokyo Ghoul dwindled the more times it fell flat on its face, especially in sequel seasons.