What's more dangerous, living life as a deadly assassin or trying to find the love of your life as quickly as possible? I can't speak for everybody, but I'm pretty sure the answer to that question would be the latter if we were to ask our protagonist, Gero. Having been trained as an assassin his entire life, he now has to take a chance to explore a completely different social ecosystem. When poison and candy are practically all you know, can he find someone to marry with his limited social experiences? Maybe, but one thing I want to praise right off the bat is that this is a personally selfless and selfish goal.

While Gero's desire to get married is done to protect his sister, who was almost forced into an arranged marriage to produce an heir to their family's old assassin teachings, Gero is fundamentally a nice guy who secretly craves a rather mundane life. I like how this is set up throughout the book's first third. Gero spends so much of his life perfecting the art of creating poisons and being a master assassin that he feels he missed out on something. So, while the initial spark was to help out his sister, adding more layers to the situation helped paint Gero in a more likable light. There's a surprisingly "every man" quality about him despite the heightened profession that he lives in.

Unfortunately, his companion Mei doesn't get as much development due to his placement in the story. While there is a bit of tragedy to his backstory, he's more of an assistant to Gero's growth than a fully realized character. I'm sure this will be further developed in later volumes, but it is admittedly a bit of a detriment for this book. Still, I think Mei is used well as a vehicle to inspire Gero and steer him socially in the right direction. Mei does get some of the best lines about how people interact with each other, what feels genuine and what doesn't. Even though this is a grimy and incredibly exaggerated world with powers that aren't always fully explained, many interactions do feel surprisingly human.

I wanted to learn more about everybody and want our leads to get a happy ending eventually. However, that might not be easy since this world leans more toward humanity's edgy and grunge side. Not only are there crime organizations and assassins running rampant, but the book's overall style has this almost dirty feel to it. Outside of our two leads, many characters' faces are distorted or warped in a cartoony way. The sketchy style elicits borderline horror vibes at times, and while I won't say that the book gets particularly scary, there are one or two moments where a character will feel genuinely off-putting. It's a very effective style that properly communicates how difficult it is to live "normally" in this world, let alone find any sense of happiness in it.

But I think that's the point. When everything is so bloodthirsty, and everyone has an ulterior motive, you appreciate the mundane much more, which gets us into the mindset of our protagonists very well. While this is a shōnen and has some of the typical shōnen tropes from intense fight scenes to borderline random, unexplained powers, the end goal is something a bit more practical compared to a more nebulous goal like being the very best like no one ever was. I question the eventual direction that Gero and Mei plan on taking to reach this goal of finding a partner with the intention of marriage by the latter third of the book. Without getting into spoilers, I'm unsure if "Operation White Knight" is supposed to be a joke or if this could be used as another vehicle for interpersonal drama later on. It's hard to say because that is a setup that doesn't get any proper conclusion in this book, but I can see the potential in that idea being explored more thoughtfully, given the rather tight writing we have here.

Overall, this is a relatively solid action series. The artwork is engaging, with a good blend of action and thematic relevance. Our protagonist, Gero, is very relatable despite his rather unrelatable profession, and I can see a lot of potential in some of the elements set up here. I wouldn't say this is a case where you have to drop everything you're doing to go read it, but there is just enough here to help MARRIAGETOXIN stand out compared to many other ongoing stories that are in circulation right now. If you're a fan of assassin stories or want an action series with a bit more of a quirky relatable edge to it, then I think this is a solid choice.