I don't really think there will be a confession at the fireworks festival because from what I saw is they're relationship is not already reach the point that will be a confession yet. Idk which chapter that fireworks arc will be, but if there's some big turning point or progress between this chapter and before fireworks festival, it can be realistic if there will be a confession at fireworks festival.
Oh anyway, I just read this manga several months ago and read from ch 1 to ch 11,5 in one day. I regulary cheking for the update but it takes a long time to finally I read this ch 12 (which updated 2 days ago). Anyone know the update interval every chapter from this manga ?