OK, just to ruin it. Eiji talked about going to heaven and meet kouki again but Kouki is a...

Fallen angel reincarnates after death

Kouki lost his powers - in exchange for Eiji's life. He's nor been condemned, so it's normal to hope to meet his loved one in heaven.

Oh man, I couldn't stop crying.

When Kouki goes back to the house where he lived before with Eiji and we see what he sees - Eiji at the window just before he passed - it was just heartbreaking ...

The whole thing bitter-sweet, but I liked it a lot.

I think he'll go to heaven