Yami To Boushi To Hon No Tabibito

I have always thought that this normal peaceful everyday life would go on forever.
—until the day I met with that incident.
Even if I had a fight with her, everything would be fine if I just apologized.
—until she was abducted by a huge red dragon that evening.
And, when I realized it, I was in a weird library. At first, I could not grasp the situation, however, soon I found out that library was a magical library with books which hold everything in the World.
I tried to return to the original World —where she is in— however, the World Book I was in was partly destroyed and I could not return. In attempt to protect my own World, to rescue her, I set off on a travel to fix the Book.