When Hidan and Kakuzu died and accepted to move to the afterlife A Diety Just out of curiosity moved them to The World of Danmachi before they could enter their cycle of life and Death, But even he didn't knows that The world he is transporting them would have to pay a huge price for His curiosity.
Hidan and Kakuzu were transported to the world of Danmachi When it's not even a day passed since Bell just came to Orario.
When they wake in their new world they would not find each other just lying side by side and they would be wearing the same clothes they were wearing when they were in Akatsuki and they would feel a bit weakened as they just crossed between Two worlds and Hidan still has its scythe but not with him he would not find it suddenly see in the story.
When Kakuzu wakes up he will be only have one heart as Kakashi destroyed the rest of his heart in his final battle with him, lets see whose heart he takes this time.
So let us go into the story of how this IMMORTAL DUO affects the World of Danmachi and their journey in Hidan obtaining his scythe and Kakuzu in search of Hearts.
Lets ------ ROCK n ROLL------