The school principal finds that she has some old toys to give away, so she decides to hold a school-wide treasure hunt with prizes for whoever can discover them. However, this hunt has a twist in that certain academic questions must be answered in order to discover the coordinates of each prize hidden within the school on an X-Y-Z plane.
Akihisa finds a lot of the prizes appealing, but he's looking forward to a limited edition set of mascot straps after seeing Hazuki's own get crushed underneath a bulldozer by accident. Unfortunately, he's been grouped with two of the dumbest people in the class: Yuuji and Hideyoshi. Because most of the questions on the treasure hunt quizzes are multiple choice, he unveils his special "Striker Sigma V" attack, which involves dramatically throwing a pencil up in the air and using the number and letter combo it lands on to make his decision. However, his first answer points to a prize drawing somewhere up in the sky that doesn't exist.
Meanwhile, the other Class F team of Kouta, Mizuki and Minami is searching through the girls' locker room. Kouta is excited at first, but then frowns when he realizes that no girls are changing in there at the time. However, the sight of their clothes in open lockers is enough to give him dramatic nosebleeds.
Back in Class F's room, the boys think they've uncovered a prize ticket, until it turns out to be a "special" basket of chiffon cakes that Mizuki made for the class. However, there are four boys and only three cakes. Remembering what happened the last time they ate her supposedly nice cooking (last episode), they end up playing Rock Paper Scissors to decide who will be the last one standing. Hideyoshi survives, but is still traumatized from the sight.
Later on, after deciding that Akihisa's strategy isn't working, Yuuji takes matters into his own hands and finds a prize ticket hidden in the gym equipment room, a ticket for one lucky couple to an amusement park complete with a "mock wedding." Yuuji refuses it, saying that Shouko is crazy enough to try and make it a real wedding. Then Akihisa asks Hideyoshi if he'd like to go, but Hideyoshi refuses, being a guy and all. That doesn't stop Akihisa from trying to confess his love to him, nor the mysterious hooded inquisitors of the FFF (again, from last episode).
After searching the entire school for the remaining prizes, Akihisa discovers that there was a prize hidden under a loose tile on the roof all along. Just as a trio from class A challenges them to a battle, the school day is over and Akihisa's trio wins the mascot straps for Hazuki, along with special bracelets that allow them to use their summons without a teacher nearby. However, when they try to test out the bracelets, Yuuji and Hideyoshi's explode (taking half of their clothes with them). Yuuji suggests that Akihisa's didn't explode because he is the "ultimate idiot."