The very first scene shows Hibiki eating some nattou while strolling down the street with Ayaka. Isn't it considered rude to eat while walking in Japan?
Considering Hibiki's general problems with food consumption in general, it may just be another facet of that. This is a girl who eats far more than she should to the point others are always boggled. So the niceties of not eating while walking may be lost on her. If not are utterly ignored because she ends up wanting food more than she wants to be polite.
