This is a side-story to The Eight-Six Duo.
Both Princess Celestia and Princess Luna never give much thought to the future. Sure, they might dwell on it for a few hours every now and again, but other than that, nothing.
On a nighttime drive with a teenage Human-turned-Alicorn named Takumi Fujiwara, the teenager asks what will happen in the future. What will happen to himself, the princesses, and most importantly, his car.