Well, with Berry’s birthday done, now comes the Autumn season. In many places, today marks the first day of the Autumn season. I can slowly see time passing by in the Yogurt series.
My guess is that Berry, Yogurt, and Risa are on their way to or from school. Along the way, Berry gives his thanks for the hat that Risa made. He knew that Risa spent a night on it, even knowing that she hurt herself too. Yogurt catches glimpse of her hands, and immediately tries to assess the damage.