The title of this story is called "The False Prophet".
In it, a new student named Kokurano arrives at YuGi's school. He becomes infatuated with Anzu Mazaki, and hatches a plan to get with her.
Kokurano lures Anzu to a classroom after school, and chloroforms her. The chloroform scene is quick, but the dialog and fain...
One of my favorite manga scenes. Gosunkugi sneaks behind Akane and chloroforms her during a chaotic Romeo and Juliet play. Akane manages to smash Gosunkugi to the ground, before the chloroform knocks her out.