When Minami challenges Akihisa to a mock battle, the ESB system suddenly glitches for no apparent reason. Several tiny clones of Akihisa's Summoned Being litter the whole school, and some guy knocks a cable loose when he tries to infiltrate the security system and fails.
As the system is glitching, the students try to summon their own Beasts, and end up with much more mature versions of themselves (including a partially lewd moment between Yuuji and Kouta's summons, leading Shouko to taser them both in real life). However, the Beings then revert to their original tiny forms, but the owners find that they can't control them as they go berserk and escape the room. Meanwhile, the principal is trying to fix the problem but because the aforementioned cable is loose she can't shut down the ESB system remotely. The only way she can do it is with Akihisa's special summoned being crawling through the air ducts, landing in the control room and reconnecting the cable by itself.
Akihisa is able to control his summon thanks to the power of the iron bracelet (see Ep #5), however, he has to deal with poison swamps (a security feature within the air duct), ill-fitting pipes (Super Mario Bros. homage) and the berserk versions of his fellow classmates' summoned beings. Will Akihisa's summon make it to the control room in time? And how can he defeat the other summons when his own is crippled by incredibly low test scores?