Anime loves to get freaky. That's the general consensus from people who don't actually watch Japanese animation and just assume it's all for weirdos. In truth, anime is a vast medium that strives to evoke all kinds of emotions across expansive fantasy worlds or heightened realities similar to our own. But yes, it does also like to get freaky on occasion, and it just so happens that the weirdest series out right now is also this season's best.
Written by Joumyaku and illustrated by Mizuki Yoda, the story of MarriageToxin revolves around a young man named Hikaru Gero who struggles with love. Like so many others, Gero is a workaholic who's caught up with his job, unable to carve out time for dating. But unlike so many others, Gero just so happens to be a professional assassin who works for the Poison Clan, using toxins to enhance his strength and kill anyone who stands in his way.
So far, so typical for usual Shōnen fare. Yet amidst all the power-ups and epic battles, MarriageToxin flips this framework into something far stranger, and as a result, more original too.
Everything changes suddenly when Gero finds out that the Clan will force his sister to bear a child if he won't marry and produce an heir to continue its centuries-long lineage. That's far from ideal because Akari is a lesbian, so she's not exactly in a rush to leave her girlfriend for a man. Gero, the ever-practical, loving big brother, asks his next target for their hand in marriage so Akari can be spared. But the target in question, Mei Kinosaki, says no. Because of course they do.
What might not be so obvious, however, is that Konsaki's actually a man who dresses up as a woman to swindle other men out of money. When Gero finds out, there's no "gay panic" around this. Instead, the pair end up becoming colleagues and even friends. Gero saved their life, and in return, Konsaki teaches him how to date women so he can find a partner he actually wants to marry, thereby saving his sister while securing the Poison Clan's future in the process.
Choose your poison
MarriageToxin is hardly the first anime to combine action with romance, but few give both genres such equal footing in their storytelling. And fewer still do so with casual queer representation like this incorporated so seamlessly.
Gero and Kinosaki's friendship is integral to this story, with a mutual respect that's often lacking when queer characters are introduced in anime. Even the opening credits show Kinosaki dressing in female clothing without judging or fetishizing them. And when you think about it, the driving purpose of the story is to help a lesbian live the life she wants and deserves for herself.
This approach to queerness isn't what makes MarriageToxin "weird" though, even if it does help differentiate the series from other action romances of its ilk. No, what makes MarriageToxin so strange is the bizarre world that Gero and Kinosaki operate in.
Aside from the strange central conceit, where a man who poisons himself gets dating tips from a cross-dressing marriage swindler, the clans themselves are also pretty weird.
Amidst all the power-ups and epic battles, MarriageToxin flips this framework into something far stranger, and as a result, more original too.
Early on, we meet Gero's best friend, the Bug Master Toshiki Hanamaki, who walks around using centipedes for shoes. Yes, really. But Hanamaki is actually pretty nice, despite that scary centipede tattoo on his face. The same can't be said, however, for the assassin made of water. Or how about the shirtless blonde guy who does a yoga-style stomach flex that almost kills Gero through the manipulation of sound waves?
Yep, these aren't your everyday fight scenes, and the show often takes weird turns narratively speaking as well. Just look at the end of episode four, when that Sound Master attack somehow leads us to a demon chowing down on a baby. "How did we get here?" you might ask yourself. That's not important. What is important is that you'll be having too much fun with all these awkward, loveable weirdos to care. And Gero might be the weirdest of them all.
The man who injects himself with poison to power up also can't eat food on dates that hasn't been prepared by him personally. He's incredibly awkward with women, to the point where you wonder how he's gotten as far in life as he has. And did I mention Gero is obsessed with DIY candy kits, collecting them like other people might hoard stamps or comics? Other characters in the show also think he's odd, probably more than we do as the viewer, but he's charming nonetheless, and that's also true of Marriagetoxin as a whole.
Strange days
Relentlessly silly and often romantic, this is a series unlike any other. Where else would our protagonist vomit up a plastic-like substance made of beer to impress? Never mind that he kills people for a living. Gero is the kind of hero you root for regardless, because his heart is in the right place. That's also why the romance and action meld far better than you'd typically find in such a hybrid show, because the action is driven by a romantic purpose, so it feels more organic.
That fluidity of genre and gender is also apparent in the animation, which Bones Film studio renders to stunning effect. The action is frantic and vibrant yet also cohesive, set to an offbeat city pop soundtrack by Taisei Iwasaki and Yuma Yamaguchi that's slightly out of step with what you might find in a similar show.
Some comparisons can be drawn between Marriagetoxin and Sakamoto Days or even Spy X Family at points, but such parallels don't really do justice to the story that Joumyaku is telling.
In a country where there's stronger pressure to marry and have kids before society deems you too old, Marriagetoxin channels the absurdity of it all with humour and also pathos, even if the show itself doesn't always make sense. And therein lies the beating heart at the foundation of it all.
Witch Hat Atelier has rightly been lauded as a highlight of this season, and a lot of fans are raving about Daemons of the Shadow Realm, too, but nothing quite beats the freaky premise of Marriagetoxin and the entirely unique dynamic that underpins it. This is the antidote to samey Shōnen that we've all been looking for. To avoid watching it at this point would be a mistake that borders on toxic.
MarriageToxin is streaming on Crunchyroll now. For more, look ahead with our list of new anime in 2026, or fill out your watchlist with the 30 best anime movies to watch right now.
