Aoi is visibly sad about Inosuke's terrible condition, since he had poison through his body and she thought it was too late to stop the bleeding. ... After this gesture, Inosuke visibly starts to see her in a good light. Eventually, she and Inosuke Hashibira marry and having a great-grandson named Aoba Hashibira.

Who married Inosuke?

It is confirmed in the Volume 23 extras that Inosuke and Aoi did eventually end up together and that they have two great-grandsons, one of which is Aoba.

What happened to Inosuke in the end?

Due to the injuries he sustained from the 'Father', Inosuke's throat became mangled, so he was taken to the Butterfly Mansion to heal alongside Tanjiro and Zenitsu, who went up the mountain behind them and was almost turned into a spider.