What I remembered is that at the end of the cultural festival a former loner character screened his film on the school wall (this is the most significant detail) with the help of his newly acquired friends. The film iirc was about all the other students preparing for the festival. The character was glad they finally had the chance to make some precious high school memories with that screening. This scene is part of more general slice of life story although that character have a specific interest in film/filmmaking.

Hyouka has a scene like that. So does Suzumiya Haruhi no Yuuutsu come to think of it...

"We can not resort to simplistic or extreme solutions which substitute myths for common sense." ― Jimmy Carter

It's not Hyouka. Can't be Haruhi since I haven't seen/read that.

Also, I should add that the film was projected to the school outer wall, so everyone at the schoolyard could see it.