I wasn't surprised when I looked up the publication info for this title to discover that it's from Shueisha's online web manga magazine Shonen Jump+, which are titles that have shonen conventions but targeted to a slightly older audience. Like fellow Shonen Jump+ title DanDaDan, Marriage Toxin is brimming with manic energy and a welcome mash of genres, from its obvious romantic comedy and yakuza story trappings to the introduction of an element-style villain wearing a diving bell (The Water Master!?) that could have come out of any shonen villain roster, with a few nods to Jojo's Bizarre Adventure.

Hikaru Gero is a Master Poisoner from a long line of poisoner assassins whose morals limit the jobs he takes to only the worst people in society. At the same time, he's the last in the line of master poisoners. When his grandmother demands that the family line continue, Hikaru's sister decides to uphold family tradition and get married, even if it means breaking up with her girlfriend and having an unhappy life.

Gero, hired to kill an accomplished Marriage Scammer, Mei Kinosaki, can't let his sister take the hit for him. So he frees Mei (after a failed, desperate marriage proposal to her) under the promise that she'll help him find a wife. That's the baseline premise, and up until here the plot is some pretty standard action/revenge/mafia manga stuff.

However, Marriage Toxin's tone changes drastically after the opening chapter to be much more of a romantic comedy, and some reviewers have found this jarring. For me, it wasn't much of an issue except that a number of fairly wild changes come into play. The cute and feminine presenting Mei is revealed casually to be male sexed, and presents as whatever gender is necessary to accomplish the marriage scam, and slots into being Gero's wingperson in his disastrous attempts at dating and courtship.

When regular dating attempts fall short, Mei suggests that Gero attempt to find a partner by saving women who have been targeted by the bad guys by scouring the dark web. This makes for some fantastic juxtapositions as Gero, mid-combat with all sorts of villains, solicits advice from Mei on basic social etiquette. It also leads into our first big fighting manga moment, as Gero takes on The Water Master, from a similar underworld family tradition as Gero, who manipulates water from inside his diving bell suit (in what feels very like a very Jojo style face-off).

The action is dynamic, but the strongest material in this book is the interplay between Mei and Gero, with his social ineptitude and her ascerbic instruction providing a lot of comedy material. Illustrator Mizuki Yoda's wonderful cartooning illustrates Gero's failure to understand social conventions, as his expressions shift from acceptably human to absurd internet-meme-style grotesque masks when he tries to connect with his dates. Though committed to being Gero's wingman, there's some obvious tension in the relationship between him and Mei that seems likely to build into a romance as long as there isn't editorial interference.

I'd give this five stars, if it weren't for the sudden tonal shift between the first chapter and the rest of the book. This feels very much like the author, Joumyaku, was advised to make changes from the editorial department after a less-well-than-expected reception to the first chapter. Making Mei gender nonconforming puts Gero in an interesting bind, in that their eventual romance means that neither Gero or his sister will be able to produce a blood heir bringing all three into conflict with the matriarch (who I'm guessing is this manga's "Final Boss"); and the whole idea of navigating queerness in a nuanced way in a heavily promoted Shonen Jump title (even with the + ) feels significant.

I'm excited to read volume 2!

I recently had the pleasure of reading Marriage Toxin by Joumyaku and Mizuki Yoda, and I must say, it did not disappoint! This manga is a perfect blend of action and comedy (with a hint of romance) that kept me hooked and wanting more. The story follows Poison Master Hikaru Gero, who is tasked with his toughest assignment yet – getting married. Gero, who is completely clueless when it comes to love and relationships, enlists the help of marriage swindler Mei Kinosaki. The duo sets off to find potential love interests, and I can't wait to see what happens next. The art in this manga is amazing as the action scenes are well-drawn and easy to follow, which is perfect since I'm usually clueless following along action sequences in manga. What truly sets Marriage Toxin apart is its message of love and acceptance. The inclusion of LGBTQ+ characters is a refreshing addition to the story, and Gero's heart of gold is one that can anyone swoon.

Overall, the first volume of Marriage Toxin is one I have to recommend to everyone. I firmly believe that whether or not you read for the potential romances, action, or another reason, there is always something to love about this series.

Thank you to VIZ Media and NetGalley for the copy in exchange for an honest review.

I didn’t know what to expect starting this manga but I’m delighted I did.

The poison master Gero never thought about marriage but when his Grandmother starts to put pressure on him and his sister to continue the poison master clan line he decides to take the fall and let his sister be happy. This is where we find that Gero is no good with women.

This action packed story is filled with humour and hints of romance. A very solid debut!!

This was an interesting premises. It was a twist on a genre I love and I enjoyed it so much. Cant' wait to see more unfold.

Marriage Toxin introduces the reader to Hikaru Gero, a poison master in a family of assassins.

Marriage Toxin Volume One
Written by: Joumyaku
Publisher: Shueisha, Inc.
English Publisher: VIZ Media
Release Date: January 2, 2024

Hikaru Gero is a skilled assassin, but he has never been in a relationship and thinks that for him, getting into one is impossible. However, his grandmother really wants either him or his sister Akari to continue the poison master clan, and Akari is already in a relationship with her girlfriend. Hikaru also makes it clear that he doesn’t want to get married just to keep the family line going. However, after meeting up with one of his assassin friends and finding out his friend is getting married, Hikaru starts to think that maybe trying to find someone and getting married might not be such a bad thing.

Hikaru takes on his next job when a group of assassins asks him to take down someone who’s been causing holdups on their gigs by using one of his poisons as a means of torture. We learn that Hikaru will only take on a job if the target is a criminal and is “human scum.” The person that Hikaru is supposed to torture appears to be a woman named Kei Kinosaki, who is known as a marriage swindler. As the two converse, Mei talks about getting into cons in order to get money for a sick brother. As the conversation continues, Mei gives the impression to Hikaru that there’s a romantic interest involved. But before anything else can be said, Hikaru’s phone rings.

The call is from Akari, who tells Hikaru that she’s going to break up with her girlfriend and bear the next heir for the clan because their grandmother has said that if he doesn’t step up, their grandmother will take Akari’s freedom away. At that point, Hikaru makes an impulsive decision to ask Mei to marry him. Mei turns him down and gives Hikaru a lecture about relationships. This leads to Hikaru spilling out his guts, and then asking Mei to be his marriage expert. The assassins who hired Hikaru try to take the two of them down, but Hikaru has some tricks up his sleeve that allows him to neutralize the threat and to escape with Mei.

But then, Hikaru gets a major surprise… Mei is actually a man. With his looks, he’s able to pull off either looking like a male or a female for the marriage swindling cons that he does. Hikaru is a little freaked out by the revelation at first, but he decides to still commission Mei as a marriage expert.

A lot of the volume shows Mei’s attempts to help Hikaru, but things don’t go to plan because of Hikaru’s inability to interact with other people with the expected social norms. Hikaru also laments that he doesn’t have any charm, but thanks to events that happen, Mei is able to find and point out Hikaru’s charm. This leads Mei to come up with the idea of Hikaru being a “shining knight” and rescuing damsels in distress. Mei introduces Hikaru to the dark nav in order to find someone who needs to be rescued.

They find that a female art thief, who says she’s stealing stolen art to return them to their rightful owners, has been taken prisoner by one of her victims. Hikaru takes on the job to save her, with Mei accompanying him. It was kind of amusing hearing Mei give relationship advice as they’re taking down guards and enemies as they proceed with their mission. But considering Hikaru’s motivation for taking on this job in the first place, this banter makes perfect sense.

The volume ends with Hikaru and Mei finding the art thief, and it seems like they’re going to rescue her… but someone hired by the “big boss” tries to interfere. The volume ends in the middle of a fight between Hikaru and the hired hand, and the dialogue that ends this scene was a great way to close things out.

Volume One spends most of its time establishing Hikaru and Mei, as well as the situation that Hikaru is now in. While there’s a little bit of action that takes place throughout the volume, the ending is the most action-packed portion of it. Considering that this is the first volume of the series, it’s not surprising that most of its pages are dedicated to establishing the characters and their situation.

When it comes to the next volume, the biggest thing I’m curious to see is how the female art thief reacts to Hikaru. We see her reaction when she learns that he’s a big name assassin, but that’s about it. When you think about how she responded to her captor’s come ons, though, it’ll be interesting to see her reaction if she finds out Hikaru’s true motivation for rescuing her.

When it comes to the art, I can say that the characters all have their own unique designs, which I always appreciate because it helps me to remember who’s who. There are also some panels in this volume that have fantastic facial close-ups. The panels near the end of the volume with Hikaru’s battle also look rather impressive.

By the time I finished reading Marriage Toxin Volume One, I thought the series showed a lot of promise. The story was interesting, and the art is quite engaging. If you’re a manga reader who enjoys stories featuring awkward characters going on a journey of self discovery while accompanied on the journey by an unexpected individual, then you might appreciate what Marriage Toxin has to offer.

Hikaru Gero has a huge Grandma problem. He is the unmarried heir for the Poison Clan and his grandmother wants an heir now! So either he or his sister will need to get married and get busy! Gero decides to sacrifice himself since his sister has a girl she really likes and he wants her to be happy. But the sap has no clue on how to woo a wife. So when he met Mei Kinosaki, a marriage swindler, as part of a job, he rescued her on condition that she help him get hitched. And then the fun begins as Gero has no experience with dating or much experience in regard to relationships at all. The comedy comes when Gero and Kinosaki are interacting and scheming. So if you are looking for a off-the wall romcom, pick up Marriage Toxin!

Thanks Netgalley for the opportunity to read this title!

I always like it when titles surprise me! I was immediately for the motive of our poison user, he wants to make sure his sister isn't forced to marry a man for the sake of having children, when she's already happy with her girlfriend. What followed was a decent look at what makes relationships work, and why our MC needs to work on himself before his con friend can help him get married, all wrapped up in action, and con artistry. Give this one a look!

This digital ARC was obtainable via NetGalley for an honest review!

Gero, a deadly poison master assassin, sets out to find someone to marry! I love that Gero was socially awkward but becomes so cool when fighting. The action scenes were really good and actually had me laughing out loud at moments!

Sure, they are assassins and crooks. However, Marriage Toxin is really just a dating/seeking a marriage partner how-to for really awkward people. I've read much worse and the dating scenarios in this book will make real life a cakewalk.

I started off really unsure of where this one was going. I think the beginning felt a little juvenile and rushed but it got better as I read on. The artwork was nice and detailed; the action scenes were clear but I actually liked the more average scenes better because there wasn't as much going on so it was less distracting. Gero is super awkward but I love it and Kinosaki is like a chameleon, showing people what they want to see to get what he wants, which usually means dressing as a girl. I didn't see how they would work together in the beginning but their dynamic is entertaining and almost flirtatious though Kinosaki is supposed to be helping Gero find a wife. The cover of the manga is what really drew me; it's a beautiful, colorful design. And the concept of the story was original with unique aspects -- Gero is a literal assassin who doesn't know how to talk to girls but is willing to find one to marry quickly to prevent his sister from having to enter a loveless hetero marriage and forget about her girlfriend. Having a con artist who makes people fall for him in seconds that Gero was originally supposed to kill become his mentor of sorts to find a wife was great since who else would be better suited to help him? This was a fun action filled manga and I look forward to seeing where it goes in the next volume.

Thank you NetGalley and VIZ Media for the ARC. All thoughts and opinions are my own.

Marriage Toxin vol. 1, with story by Joymyaku and art by Mizuki Yoda, will be released on January 2, 2004. VIZ Media provided an early galley for review.

The cover of this manga really caught my eye. With the colors and characters, it just looked like something different and interesting. It made me want to check it out.

Marriage Toxin appeared weekly in Shonen Jump starting in April of 2022 with over 70 chapters to date. The first 51 chapters have been collected in seven volumes; this is the first volume translated into English.

As the story starts, we meet Gero in an opening that could come straight out of any spy movie (right down to very bizarre behavior of a wealthy crime lord). Gero comes across as resourceful as he is handsome. We also are presented with the motivation as to why this lone killer needs to look into marriage. It is a quirky enough of a premise to pull the reader into this character-driven action tale, and the worldbuilding is top notch.

The artwork equally handles both the quieter character situations as Kinsaki walks Gero through modern dating as well as the intense action scenes of the darker corners of the world which these characters inhabit. I very much like the style of the series overall.

I will definitely be on the look out for more in this series.

This first volume is a bit of a mixed bag. On the one hand, the concept of an assassin needing a marriage consultant to find a wife is hilarious and opens up a lot of interesting ways the plot can play out. I also liked that Gero is beginning to search for a wife to save his sister, who has a girlfriend, from being forced into a het marriage. The fact that the counselor, Mei, is a man, was also a surprise. So far it's being handled well, but it being a SJ title, I do have some concerns that Mei will get played for laughs in the future. For now though, Gero and Mei have an interesting dynamic and are well on their way to becoming friends in some capacity. The flipside is a lot is happening but very little progress is made, and the plot as it stands seems a little weak compared to an otherwise solid setup the story is given. I have no idea where the story will go next, and instead of finding that fun, I find myself a little concerned. I do want to know how things turn out, but I think i'll hold out until more volumes are released.

Thank you Viz Media and Netgalley for this advanced copy.

Shonen Jump did it again! They were exploring LGBTQ in this manga. However the story didn't really have any special aspect and quiet forgettable but the combination of action in comedy in this manga was good for light reading.

I found this pretty fun! I really liked the art style and the premise is pretty neat. A master poison assassin trying to find the love of his life with the help of a con artist? Sounds really cool, right?
However, I really just didn't vibe with the characters too much and the pacing was a little... Strange. I might give vol 2 a go when it comes out, but I'm not sure.