Summer is a festival season also in Japan. That’s why there were so many festival and such related pictures posted on Kobushi Factory’s official blog in August. They were for example at Tokyo Idol Festival 2018. And of course they did also Otodama Sea Studio live. And Hello! Project had it’s 20th Anniversary tour going on around Japan.
As for members birthdays August was a month of group leader Ayaka Hirose’s Cake Day. On August 4. Ayapan turned to 19.
By the way in every other shot we can see Rei Inoue as she seem to be there where photos are taken. And if not she can always take selfies.