Mr. Usui is obsessed with Yume, a student of his, whom he considers the most beautiful of idols. One day, Yume goes in an unused classroom to have sex with her boyfriend, but Mr. Usui sees her... And he's recording.
In this hybrid of full color CG set and manga you can see the depiction of the ultimate fantasy: for unexplained reasons, everybody completely ignores the main character, no matter what he does. So of course he proceeds to fuck every good looking girl in sight.
And he does all that while his targets are going about their everyday activities, like attending PE, texting in bed or giving a public speech.
Depicts twelve different situations, each between two and three pages long.