The Death March Arc is the fifth story arc of the Eyeshield 21 series. where the Deimon Devil Bat went to America after losing to Nasa Alien and participate an extreme method of training, created by Doburoku Sakaki. It is so serious that before doing the march, everyone was warned that their lives would be insured danger if they did it. Its extremity is proven that as Doburoku got seriously injured doing it, resulting in the end of his athletic career on a whole. This arc led to the Introduction of Doburoku Sakaki the Trainer for Devil Bat Natsuhiko Taki the Tight End and Suzuna Taki Natsuhiko's Sister and the Cheerleader
This training is for all positions, done for 2000 km, going a whole day and resting in the night. It is said to be worth three years of training, within 40 days. Wide Recievers run pass routes along the 2000km nonstop, Running Backs run kicking a rock to learn how to run properly, Quarterbacks run also, practicing pass routes and carrying weight and Linemen push a truck with all the luggage and extra weight with them to gain more strength and learn Hip Explosion.
It also utilizes "Hyper Recovery". After working out, muscles get sore. The sorer you muscles are, after resting and recovering they will be even stronger. That is the theory behind Hyper Recovery. Recovery takes at least twenty-four hours however. The team uses this to a more extreme degree, by doing two days worth of sessions, going through the night and then rests for one day.
After losing to the Nasa Aliens, the Deimon Devil Bats go to America, and Nasa Aliens will stay in Japan while renewing their passports. In America, Hiruma decides that to get the team in shape for the fall tournament and thus went to the beach to find Doburoku Sakaki. Doburoku agreed to be their coach. Hiruma insisted him that they will initiate the Death March. Doburoku immediately opposes the idea, showing the team his scar but Hiruma still insists.
The next day, the team gathers at the airport, Doburoku warning that the Death March was hellish training, and once you cross the line you die and go to hell with the Devilbat. The whole team, Monta going first, accepts to go on the march and Sena reveals himself to be Eyeshield 21 to the rest of the team (excluding Mamori).
The march starts, with Doburoku giving everyone assignments (as stated above) and giving Sena a rock. He instructs Sena that if at anytime he loses the rock, he must start the Death March all over again. The team starts, Mamori still ignorant gives Sena water, which is actually Cerberus under a cover, to give to the team. Hiruma runs after the Wide Receivers, Monta and Yukimitsu, yelling out pass routes while firing shots from his gun after them. Yukimitsu at one point becomes so exhausted that he risked being cut from the team from collapsing and almost being unable to complete the Death March but Sena saves him by carrying him on his back. Yukimitsu then recovers and even goes back and runs the distance Sena carried him over and eventually finishing the Death March strong. The linemen struggle to push the Devilbat, Doburoku's truck. After training for a whole session, Hiruma explains the concept of Hyper Recovery and explains that they will go two sessions and rest for twenty-four hours exactly. After doing another session, Hiruma finally gives the worn out the team a rest, while Mamori attends to them. She chooses to attend to him first though, noticing that he was limping and realizing how hard his particular training was. While resting, Shozo Togano and Koji Kuroki plan to abandon the March, trying to persuade Kazuki Jumonji to go as well. This differs between Anime and Manga since, in the manga, Doburoku catches them, gives them a map and tells them about Hiruma and Kurita's situation. In the anime, the three get into a fight in which Jumonji beats them and persuades them to continue the march. Meanwhile, the Devil Bat truck later is almost destroyed after almost slipping into a pool of water. At first, all the linemen say that it's their job to save the truck, Jumonji even goes as far as to threaten Sena with death if they even dared to touch the truck. Gradually all the Devil Bat members join in to push and save the truck.