Den Ei is one of the squad leaders of the Hi Shin Unit. Later, a 100-Man Commander of the Hi Shin Unit.
He wears the armor of an army soldier when in battle, outside the battlefield he wears normal clothing of the era.
He has short spiky hair and no facial hair.
Den Ei has a confrontational personality to those who have not yet achieved his approval. He became respectful of Shin after he saw what he was capable of. He was completely against Ka Ryo Ten joining the unit, and was about to physically assault her until Shin stopped him. He later respected her upon seeing her capabilities.
Den Ei was brought in as one of Shin’s squad leaders, by Hai Rou. Because he told him he could earn big. Shin then informed everyone that their unit will be a special 100-man unit. That didn't belong to any division, and answered directly to general Ou Ki. And they would be sent into the most important clashes, and undertake the hardest fights. In exchange the rewards would be huge.
When they reach Bayou instead of charging the city they advance right. To avoid fighting on the open field with Zhao cavalry. Instead of charging with the left army, they are assigned by General Ou Ki personally to flank the Zhao forces while they are engaged in combat with the Qin Left Army and take General Fuu Ki’s head in the midst of the confusion. Ou Ki then bestows them the unit the name of the Hi Shin Unit. They provide by moving behind the thicket, to loop around the Zhao, to strike them where they least expect.
Then while fighting Fuu Ki’s elite guard unit, Shin splits the unit in half taking the squads that can still run, fight, and still have energy in them. When Kyo Gai says its 30 vs 300. He tells them not to worry, it might be 300 but there’s only 150 of them between them and Fuu Ki. 15 deep and 10 across, which makes 150 men. All they need to do is cut down ten ranks of soldiers and they’ll be able to reach the general. When they manage to break through Fuu Ki decides to pull back his forces to create distance. Then Fuu Ki sends out his a cavalry unit to destroy them. Bi Hei tells Shin and Kyou Kai to run, since they were mounted they could get away. But he refuses to leave his men. But they are saved by the Qin Left Army. Then, Bi Tou tells Shin to go and take Fuu Ki’s head. But Den Ei tells them not to let Shin pull ahead, because after coming this far he’ll be the one who gets the general’s head. Shin tells him not to worry. Because his had will be the one to take Fuu Ki’s head but he’ll split the reward 100 ways, for everyone there, the one’s behind, and the ones who died. When Fuu Ki splits his forces and heads for the bushes Hai Rou notices that they’ll lose him for good. But before he can make it Qin flags come from the bushes. Giving Shin the opportunity to slay Fuu Ki.
A few days later, the Hi Shin Unit was folded into the 4th army to hit the Zhao HQ with their whole army. They then charged the foot of the mountain to set up their HQ. Then they see that the Zhao had practically made it into a fortress. When they enter the Zhao start retreating. Den Ei notices that the Zhao were already long gone by the time they got there. And have moved their HQ and soldiers to a new location. While looking for the Zhao Kyou Ji says that the squad is only made up of weirdos. Den Ei tells him it’s because the captain’s strange himself. Shin then says that he’ll kick Den Ei’s ass. He tells him to come at him anytime. They are stopped by En. That night they camp in the mountains with the with the rest of the Army. When the men start to feel scared that the Zhao will attack at any second. Den Ei tells them that they are the ones attacking, and the Zhao should be the ones too scared to sleep. Later that night, they are informed that the Zhao have attacked. When they are formed into ranks, Hou Ken jumps from a hill, and starts slaughtering the unit. Shin then begins to duel Hou Ken, then Kyou Kai intervings. He then tells them his name is Hou Ken, the Zhao Army’s Commander-in-Chief. Shin and Kyou Kai pincer Hou Ken. As Den Ei is about to go help fight, he is told by Suugen that he will only get in the way, and the only way they can support them is to stand guard and watch over them from a distance. Shin is quickly blown away by Hou Ken. As he fights Kyou Kai, 500 Zhao arrive under the command of Man Goku. Shin then rises and orders his men to fall back and regroup, while Shin and Kyou Kai cover them. Instead the Kan Ou Army shows up and attacks the Zhao. During the chaos, everyone slowly finds their way back to Shin. When Shin wants them to fight Hou Ken, Suu Gen tells him that he understands his feelings, but he should take a minute to calm down and think it through. And they cannot defeat him by blindly charging like that. If they were to fail in their gambit after entering the middle of that, there’s no doubt their unit will be annihilated. Shin reminds him of when they took Fuu Ki’s head, and how many of their men gave up their lives so they could take it. And how their centre and right armies sacrificed thousands, and what they had to show for it. That is what war is. But right now, the Zhao Commander-in-Chief was right in front of them. But he agrees with him, so he asks if anyone wants to pull out. Den Ei says there’s no way they can walk away from this. And that’s enough talking and they should get a move on, and they’re going to get the biggest achievement of the battle. Shin has everyone apart from him and Seki’s squad split into three groups. Take position surrounding Hou Ken from three directions. Gathering as many of the nearby spears as possible. Then hold position and wait for the signal. On Seki’s whistle signal, all three groups made a beeline for Houken. Then threw spears at him from all three directions. He deflected all of them, but while he deflected them Shin snuck up on him from behind. He still noticed him, but Shin knew he would and dodged the swing.When he goes to cut him, Shin knew that Houken would still notice and go for another swing so he dodged it and slashed him. But it didn’t work. Before he could make another move he is hit by the backend of his glaive. And before Hou Ken can kill Shin, Kyou Kai protects him, and is blow away. Then as he goes to kill Shin, he is protected by the Bi brothers and Taku Kei. Then the unit comes to their aid, Den Ei tells them they are friggin’ amazing, and they did good. Then they retreat. They are then chased down by Man Goku. While on the run, a soldier starts wondering how things ended up as they did? Den Ei tells him to stop bitching, and its because they couldn’t kill Hou Ken. Hai Rou tells him things would have been crazy if they succeeded, they would have hero’s of their village to heroes of the state. Den Ei starts laughing and agrees with him. He then says that Shin keeps getting more and more incredible. He tells Bi Tou to hang on to him no matter what, because it doesn’t matter how many of them die, so long as he stays alive the Hi Shin Unit will never die. Then they are attacked by Mangoku. The Bi brothers manage to get Shin out. Den Ei then says that those two are good in a pinch. Then they retreat to buy them time.
The next morning this find the others after hearing Seki’s whistle. Suu Gen is heavily injured and lost an eye, is carried by Den Ei. Bi Hei tells everyone Shin will be fine in Tou’s hands. He tells them to send out search teams, and he has a pretty good idea what direction they’re in. But Seki tells them Shin has returned, carrying Bi Tou. As everyone is relieved of their return, Shin tells Hei he’s sorry. And lays a lifeless Bi Tou down.
Now having lost contact with the other Qin forces, reduced to 13 squad leaders and 36 men the Hi Shin Unit began to revive. They picked up their weapons and began to advance forward without binding their wounds. They find a Qin flag, but it turns out to be a trap set by the Zhao general Shou Mou. They are saved by the Qin cavalry lead by general Ou Ki. After a fierce skirmish Ou Ki slays Shou Mou in one swing.
They then travelled with the Ou Ki Army, when the cavalry and footsoldiers separated due to the mountainous terrain. When they reach the Zhao HQ, they learn that Mou Bu is under attack by the Zhao, and go to help him. As they are about to fight the Zhao the Zhao Three Great Heavens’ flag goes up to everyone’s surprise. Then, as the Qin’s morale is almost covered by the Zhao’s Ou Ki goes and raises the Qin’s. Hou Ken tells them that the right army will be bait to lure out the Zhao, and he will be the attacker. After Ou Ki’s lieutenant Tou engages the enemy, and exterminates their archers, the infantry charges the Zhao. As the arrows are about to come, they turn left to target the Zhao base camp. Then, Ouki takes to the field and battles Hou Ken. Shin then asks Kyou Kai who does she think is stronger Hou Ken or Ou Ki? She tells him Hou Ken, and gets angered comments from the unit. Hai Rou states that they’ve lost a lot of comrades to him. Kyo Gai says they have earned the right to see Hou Ken’s final moments. Shou Sa says that they are a special unit that answers directly to the general. And Den Ei says the only orders they were given by the general was to be “bait.”A Hi Shin Unit member says he feels bad for all the other foot soldiers, because they're the only ones there watching instead of fighting. Den Ei tells him that the spot they're in could end up becoming the fiercest fight at the drop of a hat. Shin tells then the only thing that matters right now is general Ou Ki's fight with Hou Ken.
As Ou Ki is about to finish off Hou Ken, he stops, and everyone hears rumbling. They are then surrounded by a huge Zhao army with a Great Heavens flag. The 2000-3000 spectators collapsed in an instant. And the location devolved into a huge melee with cavalry and infantry alike. The Hi Shin Unit then starts blowing through the Zhao.
During Ou Ki's and Hou Ken's duel, Shin notices Gi Ka going to shoot Ou Ki. As Ou Ki was about to kill Hou Ken, he is hit by an arrow from Gi Ka shoots an arrow catching Ou Ki off guard before Shin cuts him in two, and giving Hou Ken the opportunity to stab his glaive into Ou Ki's chest. His soldiers then drop their weapons in defeat. Then Ou Ki rises, and tells his men to never give up even until death. Then to prove it to his men he swings his glaive at Hou Ken, who easily catches it. Then Ou Ki starts pushing down cutting Hou Ken's neck. He then explains what a general is. Hou Ken then pulls out his glaive and goes to slay Ou Ki, but it's blocked by Tou. Shin then hops on Ou Ki's horse to hold him up. Tou says his unit will act as the distraction, and Ou Ki's bodyguard team and the Hi Shin Unit will escort Ou Ki to the left at full speed. Then Mou Bu and his soldiers use their last reserves to open up a route for them. At Ou Ki's final moments, he tells Shin it is impossible for him to train him. And for a great general like him to personally teach him is too food for a bug like him to begin with. And matters like those he needs to learn by running between battlegrounds himself. And delve into and overcome strife and carnage together with his men. And bestows him his glaive before dying. Half a month later, the Ouki Army, which had remained at the front lines out of caution, returned home.
During the first day of the Battle of Sai, Den Ei was shot through the arm by an arrow. However, he pulled it out like it was nothing, and carried on fighting. By the third day, he was physically exhausted and he was struggling to raise up his weapon and continue fighting.
He has good fighting skills and has endured all the battle the Hi Shin Unit participated in since it was founded