Bando is an ex-National Police Agency Special Assault Team officer who first appears when he is sent to eliminate Lucy, an escaped specimen highly dangerous mutated human subspecies known as a Diclonius.
Bando encounters Lucy on a beach in a Kanagawa prefecture, however, Lucy is at this point in her child-like alternate personality, "Nyu". Bandou is disgusted by her lack of resistance, and, figuring she doesn't offer a significant enough challenge, punches her, knocking her to the ground, and then orders his partner, Satou to kill her. When Bandou punched her, however, Lucy reverted to her normal violent, sadistic personality.
Lucy reveals her abilities when she uses her telekinetic "vectors" to kill Satou by cutting him to pieces. Bando immediately fires his MP5 at Lucy, but she blocks the bullets with her vectors. In spite of this, Bandou managed to fight with her for a while, avoiding both her vectors and objects thrown with the aforementioned vectors. Lucy, however, manages to overpower Bandou when she takes Satou's MP5 and wounds him with a burst of fire. Lucy then proceeds to cut off one of Bando's arms and gouges out his eyes with her vectors. After changing back to her Nyu personality, Lucy fled the scene leaving Bando to die, but he was saved by a homeless girl named Mayu who called an ambulance. He would later go on to develop a father-daughter relationship with her.
Determined to take vengeance on Lucy for what she did to him, he agreed to undergo operations to replace his eyes and arm with cybernetic parts but drew the line at efforts to castrate him to prevent any more Diclonius births.
Bando tried once again to kill Lucy, but was once again defeated by her. This time Lucy tore off his remaining arm and split him in half. After seemingly dying in Mayu's arms, Bando returned to the little girl with a new bionic lowerbody.
Battle vs. Revy (by SPARTAN 119)
Bandou walked through the docks of the town of Roanapur, Thailand, having traveled their in search of an arms dealer to get a hold of some heavier firepower. Bandou walked over to several large, unguarded crates of ammunition and weapons. It was almost too easy, and it would same him a lot of cash. Suddenly, a burst of fire flew past his head.
Bandou turned to see Revy pointing her PM-63 at him. Bandou dove for cover behind several crates. Bandou got out his MP5 and fired a burst of fire at Revy, forcing her behind cover, in this case in the form of a car parked on the street.
Bandou fired the M-203 grenade launcher mounted under his MP5, sending a 40mm grenade round at the car Revy hid behind. The car exploded in a ball of fire as Revy ran out of the way of the blast, firing her dual Berettas as she ran, forcing Bandou back into cover.
Suddenly, the gunfire stopped. Bandou looked up to see Revy standing with an M79 grenade launcher at the the ready. Bandou got out his dual Desert Eagles and fired at Revy, causing her to take cover as he ran to another cover, behind a dry-docked fishing boat nearby.
Suddenly, an RPG impacted the boat, blowing a hole in the side of the vessel. Bandou dove out of the way and narrowly avoided the blast, but in the process, he dropped his Desert Eagles.
Revy advanced on him, Beretta's ready. Bandou unclipped his last remaining weapon, an M72 LAW from his back and raised it to his shoulder, taking careful aim and firing a rocket, which hit Revy directly in the chest, the explosion reducing her to a red mist.
Bandou retrieved his weapons and grabbed the crate of illegal arms and drove off in a stolen boat, ready to continue his personal war on the diclonius.
While Revy was a heavily armed, violent individual who thought nothing of killing, she did not have any formal military training. Bandou, on the other hand, is a highly trained Special Assault Team (Japanese equivalent of SWAT) officer. This superior training gave Bandou the edge he needed to win this fight.