Does original still count, even though they are tamaki_(ojousama) and reira_(ojousama) from ojousama_wa_h_ga_osuki? I would think so but I am not sure since this picture does not show up in the manga.

Hmm... I would guess not, since that seems to be a commercially-published work. I only tagged it original because I didn't know and the artist had tagged it オリジナル on Pixiv. They are the artist's original characters, but don't think they count for the tag here.