chsf, we knew from Avex's website that the track 00 on RAINBOW was just a preview. They told us so.
We do know that the complete RAINBOW song will be on the next single, but that's about all the info we know as of now.
By the way, since this is a question it doesn't belong in the news section, so I'll be moving this to Enquiries. If you have any questions about how the forum sections work, feel free to ask any time.
