How the story and the epilogue tie together:

Shiki can't just postpone it forever, but she doesn't want to deny her and Komacchi's feelings either. She's at a loss, but if all the spirits on earth can reincarnate and live again, why can't a yama and a shinigami? They go to earth without any memories, grow up, meet each other, and fall in love like this. They live a long, happy life together, and at the end, when they both close their eyes that one last time, they both wake up to find that Shiki is still a yama and Komacchi is still a shinigami.

Was it just a dream, caused by some shady drug from Eientei? Or did they both really live and love like in they remember? Well, it doesn't really matter. Shiki has work that's piled up and she needs to scold Komacchi for skipping out on work again. It might have been fake, or it might have been real. Finding that out for certain, well, that's something each of them thinks is okay to postpone. At least for a little while.

...

I don't know if the author thought it out that much, but I like to think that's how it went.

Base +3