Caligula

Ritsu is attacked by students taking on strange shapes, but Satake Shogo saves him with a giant handgun. Ritsu is taken aback by the sight of him relentlessly shooting students, but he comes to realize that other people can't see the giant gun or the transformed students. Lost and confused, Ritsu returns to his home where he's greeted by his Mother who's now covered in static and repeating the same exact lines.