Nine Schools Competition V is the twelfth episode of the Mahouka Koukou no Rettousei anime.
One of Tatsuya's friends is involved in a serious accident during the competition and the other students increase their vigilance after Tatsuya reveals that she was actually a victim of sabotage.
Tatsuya and Leo are outside the hotel testing the new armament device Tatsuya created. The test gets off to a good start, and Tatsuya explains that the Fortification Magic is holding the blade in place relative to the position of the hilt, even when not physically in contact. They move onto the next stage of the test which has Leo use the device to attack straw targets popping up and charging from underground.
Day three of the competition. Mari’s semi-final match for Battle Board is about to start. Tatsuya and his friends are watching from the audience. The three competitors get of to a good start and Mari is barely ahead of Kuroki Risa, the competitor from Seventh High, as they reach the first corner of the course. Risa’s board suddenly goes out of control and accelerates. Seeing there will be an accident, Mari slows in order to catch Risa, but her board abruptly dips and throws Mari balance as she catches Risa and the pair are thrown through the barrier at the side of the course. The crowd is horrified and concerned as Tatsuya gets up and rushes over to Mari’s side.
Later on, Mari wakes up in the Susono Base Hospital. Mayumi, who had been waiting by Mari’s side, tells Mari she’s in the hospital and not to get up as her ribs are broken. Mari asks how long until she’s healed and Mayumi tells her it will take a week for the magic to fully heal her and no strenuous exercise for ten days, meaning she can’t compete in Mirage Bat. Mari asks how the race went and Mayumi informs her that Seventh High were disqualified so the final is between Third High and Ninth High. Mayumi goes on to tell Mari that Risa only had light injuries so Mari’s efforts to save her weren’t in vain. Mari says that’s pointless if she gets injured instead, but Mayumi points out that Risa would likely have received critical injuries and had her career as a magician ended, something Tatsuya agreed with. Mari is confused as to why Tatsuya was mentioned, and Mayumi tells Mari that he carried her to the hospital and stayed while she was treated, much to Mari’s embarrassment. Mayumi tells her how he ran to her side faster than the paramedics and seeing Mari’s ribs were broken at a glance, gave the paramedics instructions. Suddenly Mayumi gets serious and asks if Mari was being hampered by magic during the accident. Mari says her board did dip unnaturally at the moment of impact. Mayumi states there were irregularities in the water only seen in magic use, but neither of the other competitors was using such magic at the time, meaning it must be a third party. Mayumi tells Mari that Tatsuya also agrees with this and is investigating, though Mari wonders who could be behind such a thing.
In Tatsuya’s room, Kei asks for the results of his analysis and Tatsuya confirms it was sabotage. Hearing this concerns Kei, and when Kanon asks why, he explains that the competition has a lot of magicians on security as well as cameras to detect any illegal magic use to stop any cheating. Despite this the sequence was launched from within the water but the caster wasn’t detected. The doorbell rings, and Miyuki lets Mikihiko and Mizuki into the room. Tatsuya introduced the pair and explains he’s called them to help solve the riddle of the caster. Tatsuya explains the situation to the newcomers, and how the water was moving unnaturally, but it couldn’t have been cast from outside the water or it would be detected, but no one could hide in the water to cast from within, at least not a human. Mikihiko asks if Tatsuya thinks it was a spirit. Tatsuya asks Mikihiko if it is possible to use a spirit to cast a delayed spell with a deferred activation time to make the water cave in under set conditions. Mikihiko confirms it is but the power would be too low to matter, had Risa not lost control, the spell would have had no effect. Tatsuya explains to the others that wasn’t an accident, showing them Risa’s board accelerated when she would have decelerated, a mistake someone chosen as a competitor wouldn’t make. He concludes her CAD was tampered with, the deceleration spell replaced with an acceleration spell to cause the accident, based on the times for the final from the previous year when Mari and Risa last went head to head. Kei questions how a CAD could be tampered with, and Tatsuya says there is likely an operative amongst the staff who did the tampering during the inspection.
Mayumi discusses the situation with Hattori, Suzune, Mari and Katsuto, stating that Mirage Bat and Monolith Code are the only remaining evens in the main competition and they need to take first place I both to assure the overall victory. Mari adds that now they have to watch for interference as well. The Shiba siblings arrive and are invited in. Suzune gives rundown of the situation, stating that the points are within the predictions but as Third High are doing better than expected, the lead is too narrow so should they not do well in the rookie matches, then the Mirage Bat event will have to be won or Third high can overtake First High and win. Mayumi then tells the Shiba siblings that Miyuki will replace Mari, with Tatsuya as her engineer. When Miyuki objects, Mari tells her there is no backup for Mirage Bat, and prior preparation for the event is a major factor. Mari then asks Tatsuya if he thinks she can win, and he says it’s possible and agrees to support Miyuki in the event.
Day four, the first day of the Rookie Event. Tatsuya is working in First High’s tent chatting with Honoka. She says her match is in the afternoon, so it won’t overlap with Speed Shooting. Tatsuya is concerned about sabotage, though Honoka is unaware, and says he’ll watch her match from the side-lines.
In the ready room, Tatsuya does last minute adjustments to Shizuku’s CAD for her first match. Shizuku is so pleased with the adjustments she asks Tatsuya again if he will work for her family at least part time, though Tatsuya decline as he’s unlicensed. The work done, Shizuku heads for her match.
In the audience, Miyuki and Honoka join Erika and Mizuki to watch Shizuku’s match, though Honoka’s anxiety is really showing. Also watching are Suzune, Mayumi and Mari. Mari comments this is the first time they are seeing Tatsuya’s engineering skills in a match. Suzune reports he’s been receiving high praise from all the athletes, to the point they are bringing their normal CADs for tuning as well as the competition ones.
The match beings and Shizuku casts her spell, setting the entire scoring area as her activation zone and detonating blasts of air to destroy her targets. Suzune explains the spell Active Air Mine to her group, how it sets the area and uses set points to trigger blasts of magic to destroy the targets. She tells them it’s the opposite of Mayumi’s technique in essence and an original spell of Tatusya’s. Shizuku clears the match with a perfect score.
After the match, Tatsuya and Shizuku discuss the match and Tatsuya reminds her from the quarterfinals, it will be in match mode and her other CAD has been prepared ready.
At First High’s tent, Mari, Mayumi, Katsuto and Suzune discuss the results so far. Suzune reports all the girls passed the speed shooting preliminaries. As for Battle Board, two of the boys missed the cut and one girl has passed so far. Mayumi comments Honoka is sure to win her match. Katsuto comments they may need to nurture more engineers in future at First High.
Meanwhile Tatsuya is running around engineering for all three First High girls. Shizuku is a little concerned, but Tatsuya assures her it’s fine. He reminds Shizuku that her new CAD is different from the last one and checks if it needs adjustments, but Shizuku says it’s such a good fit it’s almost creepy. Shizuku confirms the other two girls have won their quarterfinals and Tatsuya confirms they have. Shizuku confidently states she’s going to win and heads for her match.