|“||Oi, you guys better prepare yourself for this. Baku Koshin's an insane commander who loves suicidal charges. His unit always end up with the heaviest casualties||”|
— Kyou Ji, about Baku Koshin
He has a warrior's build and is dressed in the standard armor given to every Qin 1000-man commander. The suit of armor is colored blue and has a red cape over it. He has a scar on the left corner of his mouth and a goatee.
Baku Koshin is a stern, ferocious officer who is always throwing himself into the midst of battles. He is a textbook soldier who does not deal with insubordination amongst his men and follows the orders of his superiors. One soldier comments that Koshin loves suicidal charges and his unit always ends up with the heaviest casualties.
He respects the sacrifices of his men as they are dying honorably for the sake of victory. He also shows the same kind of recklessness and toughness displayed by Duke Hyou during the battle, as he continues up the hill despite his wounds. When stabbed by General Kyuu Gen, he laughs at him, surprised he would go out of his way to stab a man that couldn't even see at the moment.
At some point in the past Baku Koshin entered the Qin Military and managed to reach the rank of 1000-man commander. Although not much about his past were revealed, it can be assumed that he has been in the Duke Hyou Army for quite a while, given that he is familiar with the Duke's ways of battling.
During the Battle of Dakan Plains he commanded the 4th infantry unit of the Qin army, organizing them into proper divisions before they engaged Kyuu Gen's troops. Koshin, in full view of his men, killed a soldier for daring to talk back to his superior. Heki chastised his action before Shou Kaku stepped in between the two men. He ordered the Qin infantry forward while the cavalry was held back on Duke Hyou's orders. While the infantry struggled with the Wei army, Baku Koshin stopped an impatient Heki from going to assist them, telling him that victory is more important than the lives of mere soldiers. After the 4th Qin cavalry unit was sent to relieve the infantry, he noticed that it was Shin and his unit that caused the Duke to make his move. Recalling what is left of his infantry unit, he emboldened them with a speech about pride in their accomplishments and told them that they will attempt to take General Kyuu Gen's head by breaking past his forces.
Koshin successfully broke past Kyuu Gen's forces at the base of the hill, but was only left with 40 men and 6 infantry with Shin leading them. Seeing that Shin took command of the remnants from the infantry, he asked him to come to the vanguard as they head for the hill. To the men with him, he promised a reward 10 times higher than normal, if they were to succeed in their mission. Using his intelligence, he saw that the dust storm could cover their tracks and told his cavalry to reduce their speed to that of the foot soldiers during their ascent. When they met the 2,000 Wei guard on the hill, he ordered his men to cut down ten soldiers per person and continue onward. When he ordered the cavalry to split from the infantry, Shin asks if he planned to use them as a distraction from the start, to which he responded that everything is done for the sake of victory.
They were then confronted by a unit of archers, is the favored defense for the generals of the strategic type. An arrow struck him in the chest but he continued on and was guarded by Shin who managed to deflect two arrows fired by Kou Rigen. He was already dying when he clashed with Kyuu Gen, laughing despite Kyuu Gen's sword being lodged in his chest. After stabbing the Wei general in the neck, Baku Koshin succumbed to his grievous wounds as his men captured the Wei hill camp.
To Kyuu Gen: "You call yourself a warrior? What a joke!".
To Kyuu Gen: "Well, Kyuu Gen? Do you think my strength right now is simply another miracle? If that is what you truly believe then you will never be able to beat Duke Hyou".