the school festival! Mitsuba and kou went somewhere together, which left yashiro(you) and amane together, it was the fireworks and him and yashiro were watching them together on the school rooftop, amane hasn't seen fireworks this clearly so it was mesmerizing for him

"Woah... These fireworks are so cool, don't you think, yashiro?"

amane looked at yashiro with a smile on his face, although yashiro was thinking about how it was weird nobody remembered that... Wasn't mitsuba and amane dead?