Full Metal Panic Overload 4! Shouji Gatou.

There's a typhoon headed for Tokyo, and Chidori and the others are riding it out in the halls of Jindai High. Soske has some concerns for their safety, however, and decides 10 bring out the heavy artillery to make a few "modifications." Their teacher will try to keep things under control, but with visions of air-to-air missiles dancing in his head, Sosuke's ready to throw caution to the wind!