WARNING: The following contains spoilers for Demon Slayer: Kimetsu no Yaiba Season 2, Episode 12, "Things Are Gonna Get Real Flashy!!," now streaming on Funimation, Hulu and Crunchyroll.
The new "Entertainment Arc" of the Demon Slayer: Kimsetsu no Yaiba anime features a brand new Hashira: Tengen Uzui, the Sound Hashira. Besides his uniquely attractive looks and cool Nichirin Cleavers that he dual-wields, Tengen also has three incredibly beautiful wives -- Makio, Suma and Hinatsuru. Even to Tanjiro, Inosuke and Zenitsu, having three wives comes as a shock when they first hear about it. However, at the end of Season 2, Episode 12, there's a tiny scene that explains why Tengen can have three wives.
Tanjiro tells the audience that Tengen's family practices polygamy, which is the act of marrying more than one spouse at a time. Supposedly, at the age of 15, the head of the family picks out three compatible wives for the son, but that's not always the case. In Tengen's situation, his wife Suma initially approached him instead of being picked by his father.
Demon Slayer: Kimsetsu no Yaiba takes place during the Taisho period of Japan, which spans between 1912 and 1926. Tengen also grew up in a shinobi family -- a family of ninjas. It therefore goes without saying that after centuries of family tradition, Tengen's shinobi family may have held onto some customs that became outdated as the years went on. The anime depicts Tengen's polygamous marriage mostly in positive ways, although they do quickly become damsels in distress pretty early on.
Despite being captured by the demon in the entertainment district, Tengen's three wives are depicted by way of Tengen's description of them early on in Season 2. The way he describes them is filled with respect and admiration that is shared equally between the three of them. During Season 2, Episode 12, there's a flashback scene where Makio remembers what Tengen tells them before sending them into the entertainment district. He instructs them to put their lives before the mission because they are his number one priority, even above the innocent citizens.
However, bringing a polygamous relationship into a contemporary anime has its risks. The wives are all kunoichi (female ninjas), yet are depicted in lewd ways in every scene, with very revealing outfits that undermine whatever physical abilities they may have. Some may even call it an affront to modern feminism in that it still places Tengen as the one in charge and indicates a power dynamic that falls in the male's favor. Still, in a shonen anime, this depiction of wives, kunoichi or not, is often familiar and almost to be expected.
Of course, shonen anime is geared toward primarily young minds, and depicting women like this could be a negative thing. Luckily, the anime is starting to show more of what these wives are made of and that they can stand on their own without any man. In fact, it's becoming slightly less of a risk to discuss the topic of polygamy in current times as more people dabble with the lifestyle, regardless of religious or political thought.
Although Demon Slayer: Kimetsu no Yaiba touches on this delicate and sometimes offensive subject, it does so with as much grace as a shonen anime can muster. It tries to give the women respect despite their revealing outfits, and it frames their relationship with Tengen as entirely equal and positive. At times, their three-way marriage almost seems wholesome. Tengen sees his wives as the warriors that they are -- and as a shinobi, he should be the best judge of all.
