An insert song of Code Geass Lelouch of Rebellion.
It's really a sad song for a tragic bond. I guessed, this is meant for Lelouch who sacrifices everything for his little sister Nunally. And also since this song is played in the initial meeting of Euphie and Suzaku, this is also a song for their love story which never meet a happy end.
 
The meaning of lyrics:

Stories
Vocals: Hitomi
Lyrics: Kuroishi Hitomi
Composition: Kuroishi Hitomi

You are my stories
Unread stories
You are my stories
Unread stories

When I gazed at your eyes
I could see an unknown country

Stories with their doors opened
Stories that won’t ever close again
Stories with their doors opened
Stories that won’t ever close again

Destiny is unchangeable
Let’s go to an unknown country

I want to protect you
Just with that wish alone
In this pitch-black world
Until the moment when light overflows

I want to protect you
Just with that wish alone
In this pitch-black world
Until the moment when light overflows

Code Geass - Stories

Mikazuki Anisa