Hold A + B + X + Y and press Start during game play to return to the main menu.
Play as Carbuncle
Complete the HaraHara course with either less than four or more than twelve fevers without any continues to unlock Carbuncle. Alternately, successfully complete the game with your number of continues as a multiple of 7.
Play As Popoi
Successfully complete the WakuWaku course under the normal difficulty setting.