Princess Yona's manga / #Historical(45)

The end game is ambiguously unclear. It is not defined what happened and who (if anyone) Tanjiro spent the rest of his life with romantically. If we assume that Nezuko and Zenitsu had children then that would explain why their grandkids look like them and Tanjiro (because same gene pool). I personally think that Tanjiro and Giyuu for together in the end. I base this off the amount of sweet/ find looks they give each other, how sad Giyuu was when he thought Tanjiro was dead (and thought back on the happy moments the two shared), and how those two bonded and seemed to have a very strong connection. Plus the photo in chapter 205, Tanjiro has his hand on Giyuu's head (which could possibly be a symbolic gesture of his fondness. There is nowhere in the story that says that he and Kanao got together or really any chemistry between them. So I think it is unjust to assume those two were end game (especially since none of the children looked like Kanao thus bringing back to Nezuko and Zenitsu having children theory) If you reread it, I am positive you can see the bond that Tanjiro and Giyuu have created between each other and see that it is much more then friendship.