Successfully complete the game. Then, speak to Kizamaro at the Denpa Udai in Kodama Town. Next, go to the school gym. Wave into the Piano network, and speak to the leader Jamminger to start a 10-in-a-row battle sequence. After you win, speak to Kizamaro again to add him to your Brother Band. Kizamaro grants MegaClass+1 and HP boosts; his final Brother Force selection includes TripSong, GravityStage, MagicCrystal3, CancerBubbleSP, WolfForestSP, and CrownThunderSP.