The Autumn Tokyo Tournament is a fictional event depicted in the Eyeshield 21 manga and anime series. It is a single-elimination American football tournament between a large pool of competing high school teams in the Tokyo area. The top three teams in the tournament represent Tokyo in the Autumn Kanto Tournament. For the series' protagonists, the Deimon Devil Bats, the tournament is their first major challenge in their attempt to win the Christmas Bowl, as unlike previous games, losing a single game will end their season. Over the course of the tournament, the Devil Bats encounter stronger and stronger opponents that they must grow stronger in order to overcome. It is unknown if there is a set number of schools that can enter the tournament, but the event that takes place in the series features thirty-six teams.
The first round of the tournament consists of only four games, in order to eliminate four teams and leave thirty-two, the next exponent of two below thirty-six. The eight teams that play in this round are the lowest eight seeds in the tournament. The timing of the end of the games as portrayed in the manga implies that games occur simultaneously in four different stadiums.
The Devil Bats play their first game since completing the Death March in the United States against the Amino Cyborgs, a team known for using medical technology to build up their bodies and for winning the championship in a different sport each year. Because Sena Kobayakawa and Natsuhiko Taki mistakenly take a train to Nagano, Sena aka Eyeshield 21, Deimon's ace, arrives late. Also, because Deimon's rookie linemen Juumonji, Kuroki, and Toganou are tense, they struggle against Cyborg lineman Aoyanagi. However, Deimon's line recovers after a pep talk from their trainer Doburoku, and Sena soon arrives. Sena easily defeats the Cyborgs' captain, linebacker Munakata, with the newly developed Devil Bat Ghost, and the Devil Bats win 38-8.
Meanwhile, the Bando Spiders beat the Nansei Hawks 3-0 with a field goal by Kotaro Sasaki.
- Deimon Devil Bats def. Amino Cyborgs 38-8
- Bando Spiders def. Nansei Hawks 3-0
- Raten Matadors def. Kyoukoudai Muscle Bombers 14-0
- Hori Fantasy Monsters def. Chuuoudai Panthers 35-6
Although the second round officially for the tournament, most of the teams play their first game in the tournament in this round. Because of the large number of teams remaining in the tournament, many of the games are won by wide margins due to the difference in ability between teams. This stage of the tournament takes place on September 18.
Four games take place in the stadium featuring the Devil Bats' match. First, the Ojo White Knights play against the Sankaku Punks, a rematch of a game in the previous Spring Tournament that Ojo narrowly won 7-6. Though bitter over this defeat and intent on revenge, the Punks are easily defeated because of Seijuro Shin's improvement and Takami and Sakuraba's new Everest Pass, a high-altitude pass difficult to defend against because of the quarterback's and wide receiver's tall bodies. The White Knights win 82-0. The Devil Bats then play against the Yuuhi Guts, a weak team whose coach has gathered helpers from the school's other sports clubs to form a new team while the actual club members sit on the bench. Because of the other sports club members' lacking teamwork, and the addition of Taki to the offense, the Devil Bats easily take an overwhelming lead. When it appears impossible for the Guts to win, the coach allows the club members to play, and they successfully score a touchdown against the Devil Bats, though they still lose 56-6.
Next, the tournament favorite Seibu Wild Gunmen play against the Koigahama Cupids, and coach Billy Horide declares the team will win by 200 points. However, in the third quarter, trailing 125-10, the exhausted Cupids forfeit. In the fourth game in the stadium, the Hashiratani Deers, led by lineman Ohihei Yamamoto, play against the underdog Kyoshin Poseidon. The Deers take an early 14-0 lead, but the Poseidon send in two secret weapons, Kengo Mizumachi and Shun Kakei, who are over two meters tall. Using his extreme height, Mizumachi defeats Onihei over and over, and the Poseidon win 31-14.
Elsewhere, the Bando Spiders score a late touchdown and extra point to defeat the Hanazono Butterflies 7-6, and thanks to a Giants defender slipping while trying to make a tackle, the Noroi Occults beat the Jyonandai Giants 6-0 (Nurse Oka takes credit for having "cursed" the Giants player). The Dokubari Scorpions use their ability to predict what plays their opponents run to defeat the Jyuujika Priests 13-0, and the Zokugaku Chameleons easily defeat the Tsukuhu Super Eagles 27-3.
- Bando Spiders def. Hanazono Butterflies 7-6
- Mitama Mariners def. Kita Eskimos 48-0
- Arito Grasshoppers def. Nakaba 99ers 60-56
- Genshigen Fighters def. Nihon Machine Guns 72-0
- Noroi Occults def. Jyonandai Giants 6-0
- Karibu Pirates def. Oiyama Lions 31-25
- Ojo White Knights def. Sangaku Punks 82-0
- Sengoku Samurais def. Raten Matadors 43-6
- Deimon Devil Bats def. Yuuhi Guts 56-6
- Dokubari Scorpions def. Jyuurika Priests 13-0
- Kyoshin Poseidon def. Hashiratani Deers 31-14
- Zokugaku Chameleons def. Tsukuhu Super Eagles 27-3
- Uraharajuku Boarders def. Tamagawa Blue Sharks 24-12
- Seibu Wild Gunmen def. Koigahama Cupids 125-10 (forfeit)
- Edomae Fishers def. Waseda Killers 81-0
- Hori Fantasy Monsters def. Ginga Rockets 13-7
According to the manga, round three of the tournament takes place on September 25. The Devil Bats' game against the Dokubari Scorpions differs between mediums, in the manga being an easy victory for Deimon 42-0 but in the anime being more difficult at first due to Dokubari's players kidnapping Hiruma. Still, the Devil Bats win 42-14 after initially trailing by two touchdowns. Another notable game takes place soon after between the Zokugaku Chameleons and the Kyoshin Poseidon. Although Habashira plays his hardest and additionally recruits the large lineman Hebii to counter Mizumachi, the Chameleons are completely trounced 0-42, and all of the team's players except Habashira give up hope before the game is over. Both the White Knights and Wild Gunmen continue to dominate, with onlookers remarking that Ojo is stronger than anyone imagined.
- Bando Spiders def. Mitama Mariners 9-6
- Genshigen Fighters def. Arito Grasshoppers 74-6
- Karibu Pirates def. Noroi Occults 14-7
- Ojo White Knights def. Sengoku Samurai 34-0
- Edomae Fishers def. Hori Fantasy Monsters 51-3
- Seibu Wild Gunmen def. Uraharajuku Boarders 107-16
- Kyoshin Poseidon def. Zokugaku Chameleons 42-0
- Deimon Devil Bats def. Dokubari Scorpions 42-14