To further scratch my Kannazuki no Miko itch, I decided to watch Kyoushirou To Towa No Sora to see Himeko and Chikane's reincarnations.
As others have said prior it is a pretty terrible anime, like it cannot be understated how bad the story and the main leads are, but whenever the focus switched to Kaon and Himiko they elevated the show massively.

The special episodes with them were especially good. I'm not going to lie, I nearly teared up when the shell necklaces showed up. They've even advanced from KnM and their necklaces form a heart now.
They are truly the Eternal Love couple.