"What is this? Is that... Shinozaki-san from class? And there's me!"
I found a video in the office of biology teacher Suzaki-sensei. Suzaki-sensei was having sex with Shizozaki, a girl everyone liked, in the middle of a lesson. It was impossible. Nobody was reacting. Even myself, in the video.
Somehow Suzaki-sensei was able to vanish from existence, at least in a sense. It was possible with a special pair of glasses.
I put them on... and I knew what I had to do next.