Looking for an anime scene involving a piano, candles and an assassination attempt.

From what I remember, the main characters were requested (borderline threatened?) to help a group of people’s friend from being assassinated during his piano performance, who was aware of the attempt.

This friend survived, because during his performance, he used the blurriness of the cooling air to make it hard for the gunmen to see where they are aiming. Does anyone have any idea of what this anime is?

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