I have frequently criticized shows for being pointlessly edgy and Martial Hearts was a particularly bad example of this. It tries to wow you with its dark plot twists and intense violence, only to come of as laughable. That raises the question of how these kinds of stories work and just why they fail so often.
When I talk about “edgy” stories, I am referring to anime and manga that are characterized for being dark, shocking, and violent. These are stories deeply rooted in cynicism, where the people are cruel, circumstances dire, and any semblance of hope or decency just exists to be cruelly snuffed out. “Everything is always as bad as it could unreasonably be” is how I have described this particular tone in the past. If handled well, edgy stories can be very interesting to watch, such as anime about futuristic dystopias or the post-apocalypse. Violence Jack is very edgy, but it’s an anime classic that I enjoy quite a lot.
An uncomfortable problem is that edgy stories often try to use controversial themes like rape and torture for the sake of shock value. Carefully establishing a grim tone for your setting takes time and effort, not to mention talent, so why not just make every woman a (potential) rape victim and make every bad guy an objectively-evil bastard instead. This can offer many advantages to the author. Simplifying these heavy topics can make even simple anime feel mature, which often appeals to younger, teenage viewers looking to get away from more “kiddie” shows. It’s also an easy way to create catharsis when those irredeemable villains are given their comeuppance and, of course, some people just enjoy watching media where everything is utterly miserable.
However, mature themes do not make a mature story. Whereas an anime like ERASED can have dark twists that really stick with people, shock value only resonates briefly and needs to be constantly refreshed. You can see this effect clearly in Akema ga Kill, which needs to perpetually one-up itself with increasingly more heinous villains for the good guys to defeat. If the last guy was a torturing lunatic, then the next guy has to be a torturing lunatic who rapes women, and the guy after that has to be a pedophile on top of that. Once you’ve grown dependent on shock value, you can only double down on it.
It is also important to stress that there is a difference between relying on shock value and just having shocking moments. Berserk is a series with many shocking scenes, but few would suggest that it’s a shallow edgefest comparable to the likes of Blood-C. That’s because Berserk has so much else to offer and builds up towards its most controversial twists; it’s a show with character arcs, intrigue, and moments of joy to create breaks in the tension.
Anime like Martial Hearts are incapable of this. They can’t handle nuanced character development and are allergic to the very idea of joy. Everything and everybody has to always be depressing, so a character who deviates from that either exists to be killed or will pull off some “totally unexpected” betrayal.
I think most anime fans can tell when they are watching a series that supports its edgier ideas with strong writing and when an anime is just exploiting those themes for cheap appeal. While you can argue about whether shows like Goblin Slayer or Saga of Tanya the Evil handle their themes well enough to justify their controversial content, most would agree that they are at least putting in an effort. No such excuse exists for the appallingly unambitious Martial Hearts.