OK, some people might already know this, but I'm putting it anyway. Before you try to cheer up someone or do a mini game, save. Then, play the game or attempt to cheer up someone. If it doesn't go how you wanted it to go, turn off you DS WITHOUT SAVING. Turn it back on, load, and you'll see that it's like you never even did that.
(I have tested it, and it works)
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