Seijuro Shin (進 清十郎, Shin Seijūrō) is one of the star players of the Ojo White Knights, and the true Ace of the team. Playing the position of Linebacker, he is known for his strength, speed, and his famous Spear Tackle. Being one of the hardest members of Ojo to pass, adding to their legacy of being the Strongest Defensive Team in Japan.
Characteristic

Shin is the fastest and strongest defensive player in Japanese history. His signature move is the Spear Tackle, a powerful one-arm thrust that can stop any opponent, and later, agonizing players so much that they refuse to touch the ball ever again (much more honourable than a spear in a real game, where the tackling player leads with his helmet).

He is one of the few characters who figured out that Sena was Eyeshield 21 right away. He does consider Eyeshield 21 as a formidable editopponent, as he admitted during the interview before the Kanto Elimination Rounds. This is because Sena is able to achieve the legendary Speed Of Light pace (40 yards in 4.2 seconds), and was the one person who actually beat him and his Spear Tackle outright with pure speed (no cuts-moves, etc.). It was through this experience that Shin was driven to improve on his running as well as his strength. He's very good at analyzing a person's moves and how to react accordingly to stop him.

Shin somewhat resembles Kenshiro from Fist of the North Star, which is used humorously in the manga to show Sena's fear of Shin (as a delusion - it's suggested that "Delusion Shin" can probably use "Hokuto-shinken" as well). Shin has been said to be the perfect player without any flaw in his ability which is because he can run at the human limit and he is near to being close in physical strength to strong players like Kurita. He's 6.2 and he grows taller and bigger every where during his last year of high school and in college.
History

One interesting note is that Shin and Sena have met previously back in grade school, though unknowingly at the time. In a flashback, Sena is running with Riku as they train to become faster. Sena almost runs into Shin as he is chasing after a car to return a 100 yen piece to a man who had dropped it. After returning the money, Shin briefly notices the small, scrawny Sena who seemed unusually fast. The memory of him seemed to linger in Shin's memory, and drove him on to become faster. The two would not meet again until much later on the football field.

Another interesting note is, Shin had signed up for the American Football team by pure chance. It was Sakuraba (for his height) that the White Knights had at first noticed, not Shin. When Sakuraba was filling out an application form, another of the seniors asked if Shin would like to sign up as well. Shin had complied, and then was noticed by Shouji, the White Knights' coach. After a while, Shin's incredible skill started to make everyone notice him, and soon, he started to overshadow Sakuraba.
Synopsis

Shin's mind is constantly on his physical conditioning. While the Devil Bats are celebrating their first victories in the Fall Tournament, they meet up with the White Knights part-way, and the two teams go to eat together at a buffet restaurant. Even then, Shin uses the hoarding on the restaurant, which is a model of a bull's head (horns and all) to exercise on, by doing push-ups and one-handed chin-ups on. Shin was based on legendary martial artist and actor Bruce Lee - his facial features seem to confirm this. Shin also seems to actually recognize person from the body build, instead of facial features (He can recognize Sena easily as Eyeshield 21) he recognized Sena as Eyeshield 21 after Sena and Monta were robbed by bikers. Shin and Sena ran after them while Shin caught up to the bikers by flanking the route they were taking and took them down off of their bikes with a clothesline punch. He recognized Sena' running style to be the same as Eyeshield 21's while he returned with to Monta with his stolen money. He also got confused when he got asked about Sakuraba new looks and during Deimon Devilbats match against Bando Spiders, he's the one who didn't get Takami's comment about Sena's releasing of his mask).

During the summer before the Fall Kantou Tournament, he trains at Mt. Fuji to perfect the 'Ballista' technique. At the end of the Fall Tournament he is voted as the MVP (Most Valuable Player), and prepares to face off against Eyeshield 21 in the Kantou Tournament.

In the anime, Shin does go up against Sena and his new Devil Bat Ghost maneuver early on. Initially he was shocked that his traditional one-arm Spear Tackle was useless against the Ghost.bSena succeeded in passing him twice. This was a rare moment in which he doubted his own ability. This led him to develop the Twin Spear Technique, using both arms to stop Eyeshield 21. Later on, he witnesses Sena develop the Devil Bat Tornado, causing him to realize that his rival was fast-evolving. He vowed to train even harder for when he and Eyeshield 21 would meet in the final showdown. Unfortunately, unless there is a major twist in the story, this is fated not to happen; Ojo and Deimon were drawn in the same half of the Kantou tournament and, providing they win their quarter-final matchups, would meet in the semi-finals.

Prior to the start of their game against the Sado Strong Golems in the quarterfinals, Shin approaches Riku Kaitani of the Seibu Wild Gunmen, telling him of a combination of the Spear Tackle with his "Rodeo Drive", creating a new technique called the "Trident Tackle". Used to crush Sado easily, the technique is actually preparation for the semi-final opponent: Sena and the Devil Bats!

At present, Shin is preparing for the semifinal game with Deimon. With the possibility of a perfected Ballista and his own Trident Tackle, combined with h