On his 16th birthday, Tomokazu Mikuri had a realistic dream where he sees a girl battling a giant floating monstrosity. When he wakes up, he is surprised that the girl is actually sleeping next to him... Whenever he sleeps from now on, he ends up back at the dream world, and more and more people that he knows keep showing up there too. He finds out from a mysterious masked woman in the dream world named Silk that they are fighting against one named Faydoom, and he is the one who provides the powers to those girls so that they can fight these monsters. And so it goes... (Source: ANN)

The science lessons are short "omake" bonus features originally present on the first two volumes. Each short lasts around two minutes, and stars super deformed versions of Noriko, Kazumi and the Coach explaining the various scientific aspects of the series. (Source: Wikipedia)

In the past Mutsumi (Mucchan) and Sae (Sacchan) met. Enjoying the time together, they decided to meet again and chose a place. Mucchan, however, never came to that place. A few years later he passed through that place on his way to school, and met Sacchan, who had been waiting for him for all those years. And so, they start playing together again. However, it won't last so long, because...

A series of shorts parodying the main series Prism Ark.