Runaway, Mazes, and Summoned Beast Instrumentality Project

The first we have Minami fussing over a photo in Akihisa's hand, then challenging him to a mock ESB, but the ESB field glitches, and the beings are acting weird, especially Akihisa's, and have taken adult versions of themselves. The principal sends Akihisa in, with his friends in the control room guiding him. But little did he know what was he going to face as his shoukanjuu clambers up the vent entrance...