Final Fantasy X/Walkthrough/We called it Sin

When the game opens, one thing that you have to do before you can continue on to the second screen where you control your character, is talk to the 2 girls that are together, and the 3 boys that are together (using X). This has confused many people, where they don't know what to do. By talking with them, you will initiate 2 different cutscenes, one with each group of people, and in doing so you can name your character (default Tidus) and move on to the next screen.