Toaru Matsuri no Triangle (とある祭りの
Touma and Index just won a Virtual-On battle against Mikoto and Misaki, the latter team bickering with each on other on why the lose. Later, Index comes across a Ziggurat burger eating competition, forcing Touma to compete. Mikoto and Misaki meanwhile finds out that the Ziggurat burger eating competition's prize is a limited edition Gekota lunch box. Misaki mocks Mikoto's proclivities for childish things, Mikoto ignore her and opts to join, forcing Misaki to follow.
However, they later find out that the competition is limited only to a boy-girl pairing. Mikoto and Misaki then bicker about the former's boyish figure. They later meet up with Index and Touma. Mikoto wants to invite Touma to pair up with her but hesitates, leading to Misaki overtaking her and inviting Touma first. Index and Misaki later quarrel with each other seeing as both of them want to be Touma's partner. To settle this, Touma agrees to pair up with both of them, while Mikoto is left alone.
With that, Touma is forced to compete as a partner for two girls, eating Ziggurat burgers twice, the two girls managing to eat their own burgers, with Misaki using her powers to eat a smaller one. Touma later goes off to get a drink an finds Mikoto alone, sulking. Touma asks why she's so down, but Mikoto won't say. Touma later recalls Mikoto being into Gekota and assumes she wants to get lunchbox, though Mikoto tries to deny it. Then the shopkeeper says that there was only one Gekota lunchbox left, much to Mikoto's surprise. Seeing the urgency and Mikoto's disappointment, Touma agrees to eat a Ziggurat burger one last time and partner up with Mikoto for the sake of the Gekota lunchbox. He takes Mikoto's hand, making her embarrassed, and proceeds to enter the competition again.
Touma has strained himself after eating his third Ziggurat burger, making Mikoto worry. But his efforts paid off as they win the last Gekota lunchbox, and Mikoto becomes happy. Fatigued after overeating, Touma can't move properly. Hearing this, Mikoto suggests, as thanks for the Gekota lunchbox, he can sleep on her lap (hizamakura). But then Misaki barges in and says that Mikoto has a hard lap, and that her lap is much shorter. In the end, Index, Mikoto, and Misaki later try to snatch Touma's head from one another to force him to sleep on their laps, much to his misfortune.
By order of appearance:
- Kamijou Touma does not recognize Shokuhou Misaki because of brain damage from the Deadlock incidents.
- The Ziggurat burger is named after Ziggurat of Ur.