At the risk of boring you, I am going to say, that eel was Nakata'a favorite food that he would dream of but can never afford because he is old, autistic man living on govt benefits....
Nakata was a famous character in Haruki Murakami's Kafka on the Shore. I don't know if you read it or even like Murakami..
but you have it, I just blurted seeing something very familiar, and yet I have never been to Japan.
https://en.wikipedia.org/wiki/Kafka_on_the_Shore
You know, I did read Kafka on the Shore, but that was about 15 years ago and I remember almost nothing of it except one of the characters loved Beethoven's Archduke Trio. I do remember enjoying it, but the overall story has just completely disappeared from my mind. I was in my Soseki phase at that point. I recall liking Botchan so much that I read it multiple times in multiple translations, trying to pick at it in the original Japanese as well. Maybe that one kind of pushed all others out.
One of these days I'm going to have to go back and read Kafka again.
You may want to read that again. In my view, and I think my view is non-unique, Kafka on the Shore is Murakami's magnum opus. I have read it many times. Everytime it feels different.