I've just scanned the manga, page 033 Omnibus edition. The best image of Osaka only a few few pages on from her first introduction.
Azuma-san depicts her here as quite pretty, with eyelashes and a more shapely face. Only later did she become so distinctly 'Osaka the Gormless'.
Here is the scan, raw.
I love this look, and want to do something with it.
Are you interested in trying a clean-up? Coloured or not I don't care.