I'm not sure about this, so I figured I post here and see if anyone here knows better than I? (I hope so...)

Is the Artist "Abubu" the same person as the Artist "Nounanka"? The first Google search I did seemed to point in that direction, and their art is eerily similar... I am posting links below, first to my Google search of "Nounanka" and then to pictures tagged by him/her on this site in order...

https://www.google.com/search?q=nounanka&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:unofficial&client=firefox-nightly

https://e621.net/post/index/1/abubu

https://e621.net/post/index/1/nounanka

Honestly, I think so, but I wanted to be sure before I changed any tags.