As of June 8, 2023, same-sex marriage was still illegal in Japan, making it the only G7 country without protections for same-sex couples, according to Reuters. Those protections include things like being able to see your partner in the hospital and make medical decisions for them, inheritance issues, and other things that most married couples don't have to worry about. This means that same-sex couples have to find ways around the lack of legal marital status to have those basic couple rights, and this slim autobiographical manga is about one of them: adoption. While that can sound a little awkward or uncomfortable to some readers because it does mean that one spouse is legally the parent of the other, Yuta Yagi's Why I Adopted My Husband does a good job of explaining how he and his husband came to their decision and how the process works.

One of the story's most striking features is how Yagi assumes homophobia on the part of his readers. That may not stand out to others as it did to me, but given who I am and where I'm from, it's a very depressing element of the volume. Yagi consistently feels like he has to justify the fact that he and Kyota want to get married, and this not only comes across in statements to the reader about how he hopes reading about his relationship will help to open readers' minds but also in the very fraught scenes where he debates coming out to his parents. Biological parental consent is required for the adoption procedure, and that means that both men will need to decide if they want to come out and acknowledge that they're more than just "good friends" or to frame their relationship progression as just two single guys who don't plan to marry finding a way to make sure they're taken care of. Different approaches are taken with each of Yagi's parents, while Kyota opts not to come out to his. In a very good display of how every family situation differs, Kyota's parents are perfectly fine with his explanation. At the same time, Yagi's are far more resistant, even when he doesn't come out to both of them. His emotional journey is much more along the lines of reminding his parents that what they want for him and what he wants for himself won't necessarily look like the same thing – his father's dreams of grandchildren, for example, aren't part of Yagi's vision. There's something horribly familiar about his attempts to reach his father on this subject, which is nicely balanced by the way that the manga frames it as an RPG boss battle, the kind where the boss' life bar keeps randomly refilling so you have to start the attack all over again.

The book also raises some interesting questions about gendered expectations. This sort of adoption works (as explained in the text) because the older person adopts the younger, which means that since Kyota is months older than Yagi, Yagi will be the adoptee. This puts Yagi in the "wife" position in a traditional heterosexual marriage, meaning that Yagi will be the partner who takes on the other partner's family name. This is something that, traditionally, very few people bat an eye at – wives are "supposed" to be assimilated into their husbands' families. It's often still expected. But when Yagi's parents learn that their son will be switching family registers, they become upset, even putting forth conditions about which family tombstone he'll be laid to rest after his eventual death. Although it isn't explicitly stated, this is an interesting aspect of marriage that speaks to ideas of both women's subservience and the assumption of what a son's duty to his family is. Yagi's parents are uncomfortable, even when one of them doesn't realize that this is being done for marriage purposes, and that says something about the underlying cultural issues.

Despite the serious subject matter, Yagi maintains a relatively light touch. The book opens with a quick takedown of gay stereotypes. It provides easy-to-understand information about the adoption process. Still, much of it is centered around why Yagi and Kyota want to get married in the first place: because they love each other and don't see that changing. They want to be able to be legally present in all aspects of each other's lives. They're already happy; they've been together for decades (having met at Comiket in 1998), and now they have to jump through some hoops to take their next logical step. All of the serious subject matter is right there in the book – Yagi's father's homophobia is probably the most difficult to handle with humor – but mostly, the story wants us to understand that this is about two people who love each other and want to get married. That's it. This thematic simplicity helps to drive home the point about how ridiculous it is that they can't just register their marriage as such, making the book easily readable while still lingering in your mind.

At the end of the volume, Yagi writes, "I just want people to realize that people like us exist and for them to stop hating us for no good reason." While this again assumes homophobia on the part of the reader, it's also a stark reminder of why that's Yagi and Kyota's assumption. Their story shouldn't have to be this difficult, and reading this book is a good reminder that our experiences of the world aren't always universal.