Mr Nakata and his companion... their story is no doubt my fave. But the narrator being the lost 15yo that he is, you can't help but feel relief for him when he gets his much needed resolution and start to be able to move on with his life. 15 is too young an age to be saying things like "I have nowhere to go back to/I have nothing to live for"...
I sort of get it now. The story is about loss - Mr Nakata loses quite literally a part of himself, Ms Saeki lost her boyfriend/'other half', and the narrator has to deal with his mother walking out on him when he was little.
Mr Nakata never really found the part of himself that he lost until perhaps his end. Ms Saeki too never really got over her loss even when she tried to live her life. The narrator also did a lot of questionable things while trying to find himself
in the end they were sort of able to finally move on. The narrator finds it in himself to forgive his mother (I prefer the interpretation that Ms Saeki was his mom after all so he got to talk to her, but the thought that in forgiving Ms Saeki who'd also walked out on someone she shouldn't have abandoned he was able to forgive his mother is also pretty