Neku's partner on the top screen can be controlled by the player using the face buttons, although players can use options to have the computer assist them. Each of Neku's partners has a card game-based mechanic; for example, Shiki's card game requires the player to match face-down Zener cards. The partner can make a basic attack after the player navigates through a pathway of arrows to select one of several shown cards using the directional pad or face buttons. By navigating to a card that fits within the card game rules, the player earns a star. Once enough stars are collected, the player can launch a powerful "Fusion" attack using both Neku and his partner through the "Harmonizer Pin" that appears on the upper right of the touchscreen (assuming that the player has not rearranged where it's displayed). The player can also help the partner character dodge attacks.