Hello! This is Nami.
I'm sorry I almost forgot about the lost thing.
Setting- I think this story was located in a suburb which had once prospered.
As time passed, young people have gone to big cities, and things that had been used were left. Also, it seemed to be set in the near past, because it was filled with sign boards, not with the electricity. Trains were moving on rails, not in the air as what many people imagine the future to be.
Symbol- The lost thing is a symbol of things which are no longer used by human beings such as phones, computers, refrigerators.
Conflict- The boy and the lost thing were in conflict with others in modern society.
Irony- He liked to spend time together with the lost thing, but the society did not accept him to keep it, because it was too big to move there. He had to leave him anywhere he should be.
Climax- It seemed that no one had room for the lost thing or any idea what it was, but finally the boy found the place for lost things.
Theme- You should not waste things which could be still used.