Assassination Classroom the Movie: 365 Days is a compilation film of the anime of the same name. At only one and a half hours long, it is extremely selective in what it depicts. It cuts out all of the inter-class fights and instead focuses upon the bond between Koro-sensei and his students. Even then, having two seasons' worth of content (47 episodes) to pick from, it chooses to star the scenes in the finale the second season. The flashbacks are justified via Karma and Nagisa, now a few years later and at the start of their careers, reminiscing about the past. As so much content is cut and it assumes the viewer is already familiar with the premise, you definitely have to have seen both seasons in order to fully appreciate and understand it. It evokes the same sad feelings the anime did. However, there are only literally 5 minutes of new scenes, which are the conversations between Karma and Nagisa, which is fairly disappointing. If you're a fan of the series, then it's worth watching a while after you finished the last episode, otherwise, it can be quite bland as there is not enough new content.