I've been looking for an R18 Kizuna Akari model for a few days now and no luck. It looks like some older uploads were taken down, as I found some dead links to MMDArchive. Best I managed to get was this:
It is unfortunately censored.
I was hoping for something more in line with the model in this video.
If anyone has a version of that model, I would be very grateful if you could share it with me. She's sooo cute!