After Tibby and the player pass the Gatekeeper Trio's trials at The Fourth Gate, they finally reach Mamarin Palace, which is not only Tibby's house, but also his mother. As Tibby explains that the guardians of Heaven World are destined to grow up into palaces like her, Colin interrupts to inform him of what has happened to his mom. He suggests the player and Tibby climb up to the top of the palace to ask her what happened face-to-face. In order to open the door however, they need to restore the flow to the Left-Hand Tower and Right-Hand Tower next to the palace. Tibby and the player are allowed to tackle them in any order they wish.
In Right-Hand Tower, the player and Tibby need to clear five Rhythm Games, namely Tap Trial 2, Jumpin' Jazz, Hole in One 2, Super Samurai Slice 2 and Right-Hand Remix, to restore its flow.
After clearing them, Tibby and the player are able to enter the palace proper.