Inmu Gakuen: "Dame... Konna ni Nacchau no wa Yume no Naka Dake nano...!"

Shinji is often a high school graduation student. He loves Mayuri, his classmate. Eventually, a school teacher, Ryoko, gives him a pendant. This indicates people may have a good dream should they sleep from it. Next night, he would go to bed, holding the pendant. However, there's nothing changed on in the morning. What's the secrets from the pendant?