ggdaydreaming

The first story, cinders seemed so calm and her last words were... i guess she's behind those (she might as well a witch)

Just my theory, an explanation for kamis revival.
Can kami return with the memories intact? Yes, under one condition: kami's will to return as of their regret and lingering with the world.
This explains why Asari was able to return as he was since he didnt want to leave shoui at all. (And there's also the help of power from the most powerful kotodama to revive him).
The reason why i find the story of himi tragedic at first but after refering to this theory everything was perfect and i cant ask for more. Himi himself realised he was in love with genma but he didnt have regret with the world so he left and no returning. His whole previous life was full of tragedy and sorrow and if he continued to live with genma with those traumas it wouldnt be fair to genma as genma was traumatized with the fact that himi wasnt his. So the new himi, the one and only made for him was just perfect, himi has no memories of the hurtful life before and most importantly he is now exclusively genma's. They get to have a new start.
I positively belive in this theory since waki once said he cannot make rikichi (?) a kami since he was a guy lived his life the fullest till the end with no regrets.