Quick Travel: System, Why Did You Only Show up Now?

I thought I had traveled to ancient times, but I didn't expect that I had traveled to the book. "Is there any quick way to go back to the system?" "I will go back after the mission is completed." What about you, why do you always disappear at critical moments? Fortunately, the male protagonist of this book is reliable. With him, I can go back soon. "I have a condition" "You said" "You can't leave me"