Being part of the Kokuhaku Yokou Renshuu series, just as "Our love has always been 10 centimeters apart" and "I've Always Liked You", it's a somewhat generic teenage romance anime. However this side story has a different angle on how usually these animes go. The ending is not predictable, it's realistic when it comes to procrastination and waiting until it's too late. It's unforgiving to most of the characters involved, but in a bittersweet way.
The best comparison would be Makeine, that had a different take on romance animes focusing more on what happens to the losers of these stories rather than the winners. Same thing there, the storyitself is not original, but the angle is.
Easily the best part of the entire series, if you've seen either the short series or the other movie this is a must watch. A very refreshing watch in the realms of the predictable and recycled romance animes. However, it's best to stick to the release order to get the most out of this movie.
