Crosspost from movies thread
If it's a movie about Shuuichi, my guess it's going to be a revenge plot related to Shuuichi's past in the FBI - like a case he solved and someone he arrested. I don't think there is going to be any major BO involvement (That would have been hyped for sure). Someone probably wanted to get revenge on Shuu for something he did for the FBI, but can't find him, so attacks Masumi to lure him out. Hearing the news about his sister ruins Okiya's stew-making plans. Jodie kidnaps Conan, rounds up the rest of the FBI, and they start trying to find the suspect and discover his motive. Meanwhile Conan and Okiya work together in the background and do all the real heavy lifting. The finale is Conan being chased by the sniper's bullets, which is stopped by Okiya/Akai sniping the guy from X00 yards away. Amuro was in Hawaii this entire time working on his tan and misses all the action. The end.
Maybe it's the lighting, but it looks like Akai is crying in that poster.