Unseen Japan

The Japan You Don't Learn About in Anime.

Why are almost 98% of adoptions in Japan of grown men? Alyssa Pearl Fusek looks at the interesting history behind adult adoption. (Picture: xiangtao / PIXTA(ピクスタ))

Why Do Adult Adoptions Abound in Japan's Business World?

Essay   Posted on November 26, 2018 in adoption, law, business, money, marriage, family • By Alyssa Pearl Fusek • Read Related Articles

When a typical Westerner hears the word "adoption", they automatically assume a child is involved. That's not often the case in Japan.

While Japan boasts one of the highest adoption rates in the world, the majority of those adoptions don't involve children at all, but rather adult men. In fact, as of 2017, a whopping 98% of all adoptions in Japan were of adult men. Japan makes it scarily easy to adopt men, and not always for morally correct reasons. Want to cover up an affair? Don't want to pay inheritance taxes? Don't want your slacker son to inherit the company you've worked hard to build? Adult adoption, or 養子縁組 (ようしえんぐみ; youshi engumi) is the way to go. But how did this practice come to be? Who exactly is adopting these adult men, and why?

The Evolution of Adult Adoption

While the adult adoption boom wouldn't really take place until the Edo period, traces of the practice can be found in an unlikely place — religion. In the 13th century, Kyoto's Hongan-ji sect of Pure Land Buddhism (浄土仏教; Jōdo bukkyō) actively encouraged the marriage of priests in order to uphold strict hereditary succession requirements. Not every marriage produced sons, however, so adult adoption became a way to secure religious and patriarchal power in the sect. The temples would do outreach with samurai and other courtier families, and adopt eligible men. These adoptions were favorable for both the Hongan-ji sect and these upper-class families — the sect could continue training priests of noble blood and proselytizing with prestige, while the families could boast of having connections with the sect and utilize them if need be. Those familial and monetary perks of adult adoption would continue on into the Edo period.

 Nishi Hongan-ji in Kyoto
Nishi Hongan-ji in Kyoto, the temple where Pure Land Buddhism was founded, as well as where adult adoption became widely practiced. (Source: Wikipedia)

During the reign of Tokugawa Ieyasu, it became more common to adopt men, especially in the samurai class. While some adoptions did occur between samurai and commoners, the majority were between samurai families of roughly the same social rank. A few factors propelled this trend, the main one being the desire to maintain the family name. If a samurai family had only daughters, they could adopt a fellow samurai's son and have him take on the family name. This would leave them to marry off their daughters into other influential samurai families. In this manner, samurai families were able to maintain the family name while placing heirs in positions of power.

Like China and other Asian countries, Japan mostly practiced primogeniture, meaning that the eldest son of a family became the sole inheritor of property, familial duties, and other assets. Second and third sons stood to inherit very little, or to even secure occupations of social status or significance. Another benefit of adult adoption was to place these sons in families who needed a head of household. As an added bonus, heads of household were exempt from having to perform military service, so families who wanted to protect their younger sons would adopt them out as a way to protect them from fighting in wars. As we'll see, adult adoption became a convenient method of getting out of undesirable situations.

Adult Adoption as a Business Strategy

Modernity, technology, and wars inevitably affected the Japanese family. The multi-generational home structure started to collapse as family members branched out. The dissolution of social classes enabled more Japanese to start their own business ventures and families. Capitalism became the premier economic form in Japan, and it became convenient, and attractive, to continue to keep businesses in the family name. That’s when adult adoption started to gain traction as a business strategy.

Let's say a CEO of a very successful company wants to retire. His only son isn't really interested in taking over the company, and is already doing his own thing. Meanwhile, one of the company's executives shows promise and expertise in running the company. The CEO can adopt this executive and deem him the inheritor of his company. The CEO can retire with a clear conscience, his only son can continue doing his thing, and the new son will continue the family legacy.

Now, you might be wondering, "Why go through all this trouble to adopt the next CEO?" That's a good question, but remember, most Japanese place great prestige on their family name and their ancestors. Japan has a rather unique family registry system known as the 戸籍 (こせき; koseki) that they hold to high regard (some might say to a ridiculous degree). The koseki lists all deaths, births, marriages, and adoptions occurring in a family. When adopting an adult male, not only are they leaving behind their family name, but they're also stricken from their previous family's koseki. (For more on the koseki system, see Unseen Japan's discussion of the marriage of Princess Mako.)

Basically, an adult male might be adopted, but on paper he will be regarded as a blood heir. When an adult male is adopted, he's expected to leave behind his family as well as his family's ancestors. It's quite tricky to be reinstated on a koseki, so these adult adoptions aren't taken lightly, even though the government makes it incredibly easy to instigate them.

The Need to "Double-Divorce" Your Husband

Divorcing couple
You think it's hard to get rid of your deadbeat husband under normal circumstances? Try getting rid of him when he's technically your brother. (Picture: photomai / PIXTA(ピクスタ))

While it's mostly the males who instigate these adult male adoptions, in recent years single women have been seeking out these adoptions as well.

Let's say a couple only has one daughter, and they want to pass on their business to a male heir. If that daughter were to get married, then the couple could adopt that husband into the family, thereby keeping the prestige of having a continuous, patrilineal line. The adopted son-in-law, or 婿養子 (むこようし; mukoyoushi), would forsake his surname and whatever assets he stood to inherit from his original family. While a bit of a tricky concept to grasp for a Westerner, this isn't uncommon in Japan, especially given the strict patriarchal structure of its society.

(JP) Link: What You Don't Know Can Hurt You! What Effect Does An Adoptive Marriage Have on the Koseki and Inheritance?

知らないと大変!養子縁組の結婚が、戸籍、相続に及ぼす影響とは? | ウェディングメディアmarrial
養子縁組の結婚と聞いて、あなたは、どんなイメージを浮かべますか? 多くの人が、男性が婿に入り、嫁方の苗字を名乗ることをイメージするのではないのでしょうか? 婿に入り、嫁方の苗字を名乗ることは、養子縁組ではありません。結婚により、夫、妻どちらの苗字を名乗ることができます。...

There’s a financial perk to having a mukoyoushi:


In the case of adoption, the inheritance rights of the parents on the wife’s side come into play. Because the inheritance tax deduction increases with the number of heirs, this kind of adoption is effective as a tax-reduction strategy.

In other words, the more heirs a family has, the fewer inheritance taxes they have to pay. If a couple had three married daughters, and they adopted their husbands, then that couple will have to pay less in taxes and have more assets to go around. As you can imagine, many people took advantage of this, so much so that in 1988 the government placed legal restrictions to stop families from using adoption as a form of tax evasion. Before 1988 there were no such restrictions on the number of adult adoptions a family could have.

(JP) Link: What are the Merits and Demerits of a Man Becoming an Adopted Son-in-Law?

男性にとって婿養子になるメリット・デメリットは? | みんなのウェディングニュース

If you have a mukoyoushi, when divorce enters the equation, things get tricky:


Even if it’s only a divorce, unless you apply for an "adoptive divorce", the relationship as a relative with the wife's family will continue, and the adopted husband will also have inheritance rights.

Basically, it's not an easy feat to simply divorce your adopted husband. You have to dissolve the husband's adoption status as well if you don’t want him getting any of your assets. In other words, you have to go through two divorces instead of just one. Yikes!

Yet this doesn't deter women from entering these kinds of arrangements. In fact, one woman has made it her mission to simplify the process of finding a mukoyoushi for single ladies seeking such a relationship. Chieko Date runs the dating site Shiawase Na Kekkon (幸せな結婚), and specifically works as a matchmaker for women with businesses and men willing to become mukoyoushi.

BBC investigates adult adoption in Japan and talks to Chieko Date about the motives behind women seeking mukoyoushi.

Adult adoption remains a constant in Japan to this day. Given its long history and economic impact, it's a practice unlikely to stop anytime soon. With Japan's declining birth rate and taxing work culture, companies and families alike are relying on unconventional ways to keep a family name alive, even if it means forsaking their original birth name and ancestors. What Japan should really be focusing on is adoptions involving actual children, not just men. What is worth more — the future of an inheritance, or the future of a child?


Brasor, Philip & Tsubuku, Masako. Resorting to adoption to avoid inheritance tax. The Japan Times, Feb 11, 2017. https://www.japantimes.co.jp/news/2017/02/11/business/resorting-adoption-avoid-inheritance-tax/#.W_T9MOKNzIU. Accessed November 17, 2018.

Moore, Ray A. "Adoption and Samurai Mobility in Tokugawa Japan." The Journal of Asian Studies, vol. 29, no. 3, 1970, pp. 617–632. JSTOR, JSTOR, www.jstor.org/stable/2943247.

Tsang, Carol Richmond. "Marriage, Adoption, and Honganji." Japanese Journal of Religious Studies, vol. 32, no. 1, 2005, pp. 53–83. JSTOR, JSTOR, www.jstor.org/stable/30233777.

Alyssa Pearl Fusek is a freelance Japan and mental health content writer living in Chico, California with her partner and one cat. She graduated in 2015 from Willamette University with a B.A. in Japanese Studies and continues to improve her Japanese language skills. She is also a published poet and fiction writer. You can check out her freelance writing work at The Japanese Pearl.


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