You were a huge fan of Sailor Moon, you loved that anime so much. That was until you were diagnosed with cancer and you only had a short time to live. So you spent the rest of that time with your family and watching Sailor Moon as much as you can before you died....

After you died, you then woke up in a room. It looked familiar...

That's when you realize that you were now in Sailor Moon as Usagi Tsukino, aka Sailor Moon, Princess Serenity, and future Neo Queen Serenity.