In Story mode, select any Ultraman except for Leo and Mebius. Continue until Mother of Ultra and Father of Ultra states that Zoffy will recover for three days. A training session with the other five Ultras will begin. Complete the first fight. Press Start in the center of the second fight, then exit and save the game. Return to the PSP "Home" screen, enter the system settings, then advance the system date by three days. Continue Story mode and complete the training session. An alternate Story mode will play out. Press R during the battle with Temperor Seijin to get a clue from Father of Ultra on how to win. During the battle, increase your power into the yellow area and allow Temperor Seijin to max his power. Let him use his power, then quickly use shield. His beams will reflect back to him. Complete Story mode to unlock Ultra Father.
Play through story mode to unlock Ultra Father.