SS Case 2 is perhaps the most trivial entry of the film trilogy, but it pulls through because it's a trip back in time to the better days in season 1. But as for why the film is trivial - Teppei has always been and feels like a background character. It's his story and the resolution has to do with him, but he doesn't feel like the MC like Akane, Ginoza, Mika, or Kogami do. But as for why the film works? Division 1 is back. Kogami, Ginoza, and Kagari's teamwork is a delight to see, especially Kagari who we thought was never to be seenagain. Aoyonagi and Masaoka also return, and the film serves as a fitting final appearance and send-off to Masaoka, given the unfortunate but also perhaps blessed timing that this was his VA's final project.