Take Flight, Little Birds! - S1.E11

In order to reach the people who supposed the crowdfunding campaign, chun×4 are going on tour to various locations. The first stop is Chisa's hometown, Niigata. As soon as they get there, the four jump right into an interview with a local paper and a radio show, but for some reason Chisa doesn't look too thrilled... When the other three ask her what's wrong, she ends up raising her voice at them. What could have caused this, when Chisa is usually so put together?