In Chaos Rings for the iPhone and iPad, you can unlock more characters to play the game with.
To unlock the extra characters, you need to beat the game. Once beaten, do no start a new game but load your old game and beat it one more time. Once you do this, save your game and you will have extra characters to choose from on the character selection screen. You’ll now be able to choose the couples Ayuta and Mana, or Olgar and Vhati.