Daihaseisai

The Daihaseisai (大覇星祭（だいはせいさい）) is an annual large-scale sports festival which takes place in Academy City. Occurring between September 19th and September 25th,  during which Academy City is partially open to outside visitors,    the week-long, city-wide, inter-school sporting competition sees students from all schools competing in various athletic events,    with the use of esper abilities permitted.

The Daihaseisai is a major milestone in story of the Toaru series, with two story arcs occurring during the events of the festival, one in Toaru Majutsu no Index and one in Toaru Kagaku no Railgun.

Principles
Daihaseisai is a famous Academy City competition where students from various schools compete against other schools in numerous athletic events. During the week of the competition, Academy City is packed with tourists and the students' parents. The city-wide sports meet is broadcast worldwide, with ratings comparable to even the World Cup. Because of this, it makes Daihaseisai an inherently viable political tool for Academy City.

During this week, people are usually prohibited from entering school premises, in order to avoid outsiders from seeing the power development facilities unique to Academy City schools. Sports grounds also tend to be heavily guarded in order to prevent people from stealing DNA maps of high level espers.

Participants are encouraged to use their abilities during the matches, which is why the high-class schools like Tokiwadai Middle School excel during it. In some cases where events are held in the general public, abilities past a certain threshold, specifically the Level 5s, are forbidden in case they harm people, like when Mikoto was in the 'borrowing-items race' she could not use her powers as it was too dangerous, even if she restrains herself. These restrictions don't apply in other matches where it is only school versus school. Schools are ranked according to their scores based on their wins and losses, and the highest one becomes the champion of Daihaseisai, though only the top 5 schools of Academy City are the ones that are truly competing for the championship. Each school divides its own students to a red and white team, with the number of wins each colored team gets, the points earned would be added on to the school's score.

Although it is a large-scale sporting event, not all the students would be bounded by the events all the time. They just need to follow the rule of reaching the area in the specific time, and any time other than that was free time for them. Schools are even allowed to set up stores to get some earnings like the management or home economics schools that Tsuchimikado Maika is in.

According to details in a pamphlet given to students, the main purpose of the festival is to observe large-scale interference between Espers. The Daihaseisai is also used by people to evaluate the esper development program of each school, and thus affects the budget of each school receives.

Preparations
Preparations for the Daihaseisai are performed weeks in advance, with the Daihaseisai Management Committee, composed of students, doing the work and preparation, such the layout out for the roads to prepare for the oncoming traffic, as well as refereeing competitions. They are separated by the levels of education. For example, Fukiyose Seiri is part of the High School Division of the committee. Academy City Board of Directors are able to contact this committee as well and can order them to do specific things. Committee members are not exempted from taking part in matches however in spite of their duties, as such they had to arrange their work schedule such that it didn't affect their own matches.

Schools prepare well in advance as well, training for the upcoming competitions. An example of this would be Tokiwadai Middle School, more so during the current year of the timeline after they came second to Nagatenjouki Academy last year, setting up a school-wide P.E. lessons for the Daihaseisai. For the festival, both Judgment and Anti-Skill like Uiharu Kazari and Yomikawa Aiho respectively are deployed to keep peace and order and aid outsiders.

For transportation, other than the rerouting of traffic flow by the Committee, the Daihaseisai marks the widespread use of automated buses in restricted conditions in spite of the difficulty of using them, while ordinary vehicles are banned, though taxis, delivery trucks, and ambulances and likely other emergency vehicles are still allowed.

Rankings
Nagatenjouki Academy was the previous year's Daihaseisai champion with Tokiwadai Middle School at second place. The current year's Daihaseisai has both schools retain the previous year's ranking.

Background
In the past, there have apparently been a number of incidents during the Daihaseisai which have not been made public, including spiritualists attempting to bomb a stadium and anti-AI people attempting to destroy an unmanned helicopter.

In previous festivals, the top rankings have mostly been fought for and occupied by the top five schools. In the year before the current year, the festival's champions were Nagatenjouki Academy with Tokiwadai Middle School as the runners-up.

Orsola Aquinas Rescue Arc
Tsuchimikado Maika mentioned the Daihaseisai along with many other activities and events in the second semester. Preparations for the festival were underway across the city, including at Touma's school, with Touma being asked to set up (and take down) a tent. Security at the outer wall was noted to be somewhat lax during the preparations and run-up to the festival.

Tree Diagram Remnant Arc
Shirai Kuroko mentioned that School Garden won't open to outsiders even during the Daihaseisai.

Daihasei Festival Arc
Daihaseisai takes place on September 19 during volumes 9 and 10. In the volume 9 prologue, Touma makes a bet with Mikoto that his school will beat hers, which leads into the premise of volume 12. During the event, Touma doesn't actually participate much, as the majority the 19th is spent chasing after Oriana Thompson along with Tsuchimikado Motoharu and Stiyl Magnus. While they pursue Oriana, they try to learn the real goal of Oriana and Lidvia Lorenzetti. Along the way, Himegami Aisa is hospitalized due to a misjudgment by Oriana, Fukiyose Seiri is also hospitalized by touching one of Oriana's traps, and Motoharu is injured several times. After pursuing Oriana until dusk, Touma manages to defeat her, but it turns out his efforts were futile, as not only did Oriana not have the relic to thwart their plan, the magicians' plan wasn't going to succeed since the beginning. In the end, Touma is hospitalized from the injured caused by Oriana, and in the next day, he was alright, but got into all sorts of unfortunate events for the rest of Daihaseisai, finally winning first prize in a lucky number contest on the last day of Daihaseisai, which earned him a trip for two to Italy.

La Regina del Mare Adriatico Arc
On the last day of the festival, Touma won the first place prize at the Visitor Numbers stall; a seven day trip to northern Italy, which would result in him and Index being in Chioggia and getting involved in the incident involving La Regina del Mare Adriatico.

Academy City Invasion Arc
On September 30th, when students were picking up their winter uniforms, measurements and orders for which were made around the time of the Daihaseisai, Touma accompanied Mikoto as part of the penalty game for having lost their bet during the festival. It was noted that the underground mall they visited, which had sustained damage during the incident on September 1st, was repaired quickly due to the Daihaseisai occurring soon afterwards. Later on, Accelerator passed a load of leftover child-focused medical kits from the festival.

Skill-Out Uprising
During a conversation amongst Touma's class as to where they should all go out for dinner, one of them referred to something which was launched during the Daihaseisai. At this point, they were also said to now be familiar with Index since she had barged into class five times since the start of the Daihaseisai. In a discussion with Yomikawa Aiho about her freeloader moving out, Tsukuyomi Komoe mentioned how Nagatenjouki Academy were the champions of this year's Daihaseisai, beating Tokiwadai Middle School.

Daihasei Festival Arc
The Daihasei Festival Arc in Toaru Kagaku no Railgun takes place at the same time as the one in Toaru Majutsu no Index, primarily covering events on the first two days of the festival, though it mainly focuses on the second day rather than the first. Additionally, while the Daihaseisai still serves as a backdrop for the main events of the arc, there is more focus on the games early on, with Misaka Mikoto herself participating.

During the preparation period, the higher-ups requested performances from the Level 5s at the opening ceremony, though the committee were only able to get Shokuhou Misaki and Sogiita Gunha for the athlete's pledge. On the day, Gunha ended up improvising after forgetting his lines.

On the first day, Mikoto participated in and won the Three-Legged Race with Kongou Mitsuko in place of the wheelchair-bound Shirai Kuroko. After the conclusion of the incident on the second day, while returning memories she had erased, Shokuhou covered up Mikoto's absence from the second day's events as the result of an upset stomach. In the subsequent days, Saten got first place in the Baseball Bat Race, Wannai Kinuho participated in a Cavalry Battle, and Kongou managed to recover in time to team up with Mikoto again. Near the end of the festival, Saten arranged for Mikoto to dance with Touma at the Folk Dance after noticing her reaction to him, with Uiharu briefly restraining Kuroko.