ASAS/DD was named that at the begining of the video, but at the same time the music playing in the background was called "Another Side", so that was just more confirmation to call it that
Sunset Horizon's video had no official name, but we still had a name for it due to the KH2 OST presenting the title of the music playing during the video, so it was dubbed Sunset Horizon
And we didn't called ASAS/DD "We'll go together", did we? Or "You're the source of all heartless video"? Or "You look just like him"?
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By the way, Nomura confirmed that no one in the secret video is Sora, Riku, Kairi, Namine, or Roxas, but he said that it doesn't mean that the people in the video do not have some connection to them