Hey all- here's another thread that I found helpful, vidness lists more offsets including for adding a rune as a reusable item in your inventory: http://forums.shoryuken.com/discussion/comment/8456745/#Comment_8456745
@Xdqwerty, Osu! Tatakae! Ouendan! is the Japanese version of the game, different settings/characters/songs but otherwise identical mechanics. I played that before I knew about Elite Beat Agents lol. Both fantastic games https://en.wikipedia.org/wiki/Osu!_Tatakae!_Ouendan