After talking with Yellow 8 in IRC yesterday I've made a video in hopes to help anyone else out that wants to play their games. It shows what happens if you only delete sys data and not save data and then how to fix it YOU WILL DELETE YOUR SAVE DATA ALL OF IT
@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