I have a question about special relativity, which is set in the context of the science fiction anime Voices of a Distant Star, though it is independent of that context.
Mikako goes on a spaceship with a speed of $0.99999c$, heading towards a star system 4 light years away. In her rest frame, the journey takes a few days, but for her friend Noboru on Earth it takes approximately 4 years.
Now when Mikako arrives at the star system, she sends Noboru an e-mail at light speed, which takes another 4 years to arrive.
So 8 years after Mikako departs, Noboru gets an e-mail, inviting him to meet with Mikako.
Suppose that after sending the e-mail, Mikako immediately heads towards earth in her $0.99999c$ spaceship, while Noboru gets a similar spaceship and heads toward the direction of the star system. In a few days' rest frame time for both of them, they meet in deep space. Mikako then gives Noboru an album of pictures of the star system.
This seems like a paradox. When Noboru gets the e-mail, he is 2 light years away from Mikako. But a few days later in his reference frame, he obtains the pictures of the star system.
Why does this work? Is this not a paradox due to the fact that Noboru must wait 8 years for the e-mail to arrive? Or is it not a paradox due to relativity not working the way I expect it to work? Yet even from Noboru's $0.99999c$ perspective, Mikako's relative speed should never exceed $c$, so why, from Noboru's perspective, do the photos seem to be transmitted superluminally?