This gallery is incomplete. It is a sample from 2015.
I just happened to stumble across the first few images on pixiv. It doesn't look like the author has been active for a long time so unless someone is able to find an older copy from 2015 or 2016 I think this one may have been lost somewhere in the vast internet.

https://www.pixiv.net/en/artworks/54217927

Best of luck if you can find the full copy.

RE: tag 'japanese'

>Default language flag; do NOT use this tag outside of legitimate dual-language galleries and translations to Japanese.

https://ehwiki.org/wiki/japanese

Base +31, AlephFish +16, observer1980 +21