When I saw the title
my mind translated it as
Your unknown story (Translation A)
However, by searching a little, most sources seemed to translate with the meaning
The story you didn't know about (Translation B)
The way I'm thinking, の relates the nouns 君 and 知らない物語, indicating the later is possessed by the former.
Summarising, my questions are the following:
- Is hypothesis A wrong? If so, how would one express "Your unknown story" in Japanese?
- What is the reasoning behind hypothesis B?