Last Giyuu remembered was that he and the other remaining pillars as well as Tanjiro and the boy's friends were fighting Muzan along with a mysterious Upper moon that they didn't know existed. To attain victory he sacrificed himself to take a blow from uppermoon directed to Tanjiro. But how was it possible that he was now looking at the concerned and mildly shock face of his long dead best friend, Sabiro. //A convenient attack from an OC Upper moon sends Giyuu into a parallel world where he was the one that dies and Sabito survived. A fic where every pillar is alive// -Is inspired and greatly base by the story 'Blue' by KuriKuri on Archive of Our Own-