Inosuke doesn't know what marriage means. So to help him figure out. He and the rest of the trio have to get married for 1 week. This will all mainly be Inaoi (Inosuke x Aoi). But also Tanjiro x Kanao, Zenitsu x Nezuko, Mitsuri x Obanai, and Shinobu x Tomioka. Just to clarify, none of the images are mine. I have also never read, or watched all of Demon Slayer. So if they act a little out of character, I do apologize.
8 parts