Moero! Nekketsu Rhythm Damashii: Osu! Tatakae! Ouendan 2 Question
Exactly, thanks Japillow! I was looking for this too.
I just started the game, holded only L+R+A+B+X+Y and used my left thumb to pass the warning screen.
Then a black screen with a "Do you want to erase user data? Yes / No" (in japanese) message appeared.
Clicking "Yes" will delete the user data.
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