Johanna also gets to take part in the gymnastics gala in these Games on 24 August, in between special performances from Olympic and world champions.
"I am happy and proud to represent Greece, but nervous at the same time," she admitted.
And Johanna hasn't just got the next four years planned out; she knows exactly what she wants to do after that too.
"I hope to be a very good gymnast and maybe win a medal in the next Olympics and then maybe become a dancer in the royal ballet in London."
And if she keeps on working this hard, she could well achieve her dream.