Our very last book

Every day, Shuichi sits alone behind the school, reading his book peacefully, almost as if he enjoyed being lonely. But it was not always the case, as he used to be social and cheerful. Kokichi gets intrigued and worried by his unordinary behavior and decides to approach this outsider to get some answers.

Will there forever be an animosity between these two? Or maybe a long awaited frienship could bloom? Perhaps even more?

As usual, I don't like spoiling in the tags, so I will write some trigger warnings here. Ignore them if you prefer discovering the story as it goes.

TRIGGER WARNING!
Later in the story there is going to be a the death of a major character.