WARNING: The following contains spoilers from Demon Slayer: Kimetsu no Yaiba Volume 23, by Koyoharu Gotouge, available now in English through VIZ Media.
When the final chapter of the Demon Slayer manga was released in May of 2020, readers were introduced to the various descendants and reincarnations of the main cast. The revelation that each of our heroes had begun a family in the years after Muzan's defeat was jarring, considering the previous chapter had only briefly hinted at possible romances in the slightest of ways. Demon Slayer: Kimetsu no Yaiba Volume 23's bonus material definitively confirms the romantic pairings that fans had only been able to speculate about.
Without much context, Chapter 205 covers a day in the life of new characters who all bear striking resemblances to the original cast. While some of these children are clearly the descendants of Tanjiro, Nezuko, Zenitsu and Inosuke, what's not abundantly clear is the identity of the other parent in the equation. Fans formed their own theories after some hints in Chapter 204, but Volume 23 puts the discussion to rest. Demon Slayer's match-making is canonically confirmed thanks to a handy chart that's been placed after Chapter 205's original conclusion.
The primary children of focus in Chapter 205, Sumihiko and Kanata, are indeed the descendants of Tanjiro and Kanao, four generations later. Proof that nothing is impossible with perseverance, Yoshiteru, Toko and their two unnamed sisters are the great-grandchildren of Nezuko and Zenitsu. And it turns out Inosuke is easily won over, as his apparent crush on Aoi after she made food for him in Chapter 204 did lead to a relationship, as they are the ancestors of Aoba Hashibira.
For any readers who may not have picked up on the hints of romance in Chapter 204 the first time around, the new material in Volume 23 makes Chapter 205 worth another read thanks to this extra information. In addition to the chart, there is also a panel montage exclusive to the book that provides glimpses of Tanjiro and Kanao, Nezuko and Zenitsu, and Inosuke and Aoi all falling in love in various touching moments. These new panels provide the emotional investment in these relationships that the matter-of-fact chart does not.
In addition to the descendants of the main cast, Chapter 205 is also filled with characters who resemble the rest of the main characters, even the Hashira who lost their lives during the final battle against Muzan and the Upper Ranks. The notion of reincarnation is introduced in the opening pages of Chapter 205, though the audience is left to wonder which of these lookalikes are descendants of the original cast, and which are reincarnations.
Tojuro, the boy who resembles Kyojuro Rengoku, is identified by Volume 23's chart as a descendant of Senjuro Rengoku. The lookalikes of Sanemi, Tengen and Giyu are also descendants of the original characters. The general rule of thumb in this chapter appears to be that any of the new characters who resemble those who died during Demon Slayer's run are reincarnations. There is no explanation pertaining to the lineage of the lookalikes of Himejima, Genya, Iguro and Kanroji, leading to the conclusion that these characters have been reincarnated, given that they all died in the final battle against Muzan and the Upper Ranks.
The helpful chart also gives some background information regarding the various reincarnations of the fallen Hashira. Himejima is now a nursery schoolteacher while Genya is a police officer, sharing a brotherly bond with his partner, Sanemi's descendant. The most heartwarming revelation of all is the confirmation that Iguro and Kanroji kept their promise, as their reincarnations have found each other and have five children together.
Demon Slayer: Kimetsu no Yaiba Volume 23 does an excellent job of providing additional context to the manga's complex ending without invalidating any of the original material. Sure, many of these things were initially left for the fans to decide for themselves, but it's great to receive an additional, rewarding perspective on the resolutions of each character, especially those who gave their lives to rid the world of Demons. Volume 23's bonus material beautifully reaffirms that everyone got their happy ending -- except Muzan.