I can add a related note, that it's worth scouting Twitter and some photography platforms like Flickr - there are hundreds of photographers serving photos from photosessions, meetings and performances, even up to 6000x4000. With some luck, this means hundreds of photos for a given girl, sometimes professional-looking.
You are right. There is so much photos from different events gravure models do. Like most gravure models do these so called "Fan photo meets" where a fan
if he can afford it can take a few photos of their favorite girl. But these sessions are very regulated and one can't exactly take photos that are in gravure
magazines of how the women appear in their IV work. You won't find any explicit poses or revealing outfits in these photos. Its more like normal
model shoots. Some women do bikini and swimsuit shoots. While others only do fully clothed.
Its also worth checking sites like ameblo where some photographers post their
photos. There are also Japanese sites similar to flickr like Photo Zou.
When it comes to Chiaki I have vacuum cleaned and saved every photo I could find.
There ain't exactly hundreds of photos of her sadly.
She did most fan photo sessions a way back so it's hard to find them in really good
quality. I will uploaded everything here.
I have also collected all I could find with other gravure models I like and I will
try upload them here at akiba.