what is it?

I'm confused but still want to point out my opinion.

So the normal one in the story is Takumi right?
Because Yuzuru definitely has a potential for becoming like his father and Ayato is the one who's burning everything that Yuzuru afraid of.

But, still the end of story when they're disappeared after the boy turn away, is it possible they're becoming spirit and eternal.

But one thing I'm sure is this story so sad.