I always asked myself who the girl on the right between Chi and Sakura is as the picture is quite unclear. (Is the mascot under the poll based on something btw?)

I also read EU/US comics and am a librarian.
Manga-Masters, My ANN-Lists + Imdb

No clue about the banner girl.
For the mascot, blakraven66 provided some anecdotal description when he published it

Thx. I am happy to see that the girl is an actual challenge and i can see the similarities to Jhonen Vasquez´s Gir.
The banner art was already in place in 2005 ([url]http://web.archive.org/web/20050101000000*/https://www.mangaupdates.com/[/url]) so i at least narrowed in criteria.

I also read EU/US comics and am a librarian.
Manga-Masters, My ANN-Lists + Imdb

The eyes kind of remind me of Fate/stay night. But then the expression on the cuter side.

I've been asking myself the same thing