Like his father Akakabuto, Monsoon is a huge bear with a red-furred back. Currently, it is unknown how large he is, as his father's size was due to a mutation. It is said that his size was due to his burning hatred of the Ou Army and his continued training to grow stronger to defeat them. His kin are a lot smaller than he is, as he towers over them.
Monsoon has two scars across his left eye and his left arm is much larger than his right arm due to him being born left-handed and constantly using it in battles, which made it grow to an enormous size. Later, his dominant arm also has somewhat blunt claws, due to using it a lot.
The fur covering his left arm is golden, a trait not seen in any of his other family members.
He has a slashed left eye and he got it from Akame.
Monsoon is very similar to his father in personality as much as his appearance. He is very short-tempered and not afraid to kill anyone who stands in his way. Unlike his father, however, Monsoon was afraid of dogs due to his traumatizing past, in particular, he is afraid of John who killed his Mother and his siblings, and almost him. Upon hearing of John's death, he quickly relaxes somewhat but still fears dogs because of his trauma.
In regards to his kin, Monsoon treats them more like henchmen than brothers and is quick to anger when they fail him. Bob is no exception as well, as Monsoon sees him only as a tool which he can use as he want.
In a very rare instance of mercy, Monsoon allowed Sirius to take the bodies of his comrades away for a burial, the reason he did so was because a young Gin saved him as a cub from being killed by John, and so Monsoon repaid the favor once.
After many tries, Sirius got to reach this bear and since then Monsoon started to get an conscience. He accepted Sirius as his friend though he's still distrustful against him, fearing him to betray him someday. But Monsoon protects him and plays around with him, without injuring him, even if he first tended to be too violent and too rough while playing. But he learns time to time and starts to be more patient and careful, the closer their friendship gets.
Sometimes he still has thoughts of killing Sirius when getting angry but he rather takes his anger out on surrounding objects than on him. After all he can get aggressive fastly if he feels betrayed or manipulated, even just of small things. But Sirius now got a place in his heart and he can't come to injure him even if thinking of it. Since Monsoon gave him his trust he can get hurt and feel betrayed easily, always thinking of the worst first. He even shed tears of pain when he thought that Sirius betrayed him.
Ginga: The Last Wars
Monsoon is one of the many sons of Akakabuto. He, along with his brothers, were attacked by Ou's dogs and in order to survive they escaped as their mother stayed behind to fend off the dogs so her children could live. Monsoon and his brothers struggled to survive on their own at such a young age. Eventually, he became adamant at taking back Futago Pass, which once belonged to his father.
When Monsoon was still young, he stumbles upon a wooden box in the forest and breaks it open to inspect the contents, immediately fleeing when he discovers the box is full of puppies. He stops to hide behind a tree and watches from afar, but the puppies make no actions to harm him and are simply grateful for their escape.
Monsoon tries to scare them away but this only confuses them, in turn making Monsoon angry. His brothers arrive and try to kill the pups, but are stopped by Monsoon, who inspects the pups again and is licked affectionately by one of them.
However, the pup playfully nibbles on his claw, causing the bear to panic and crush the pup without a single trace. The other pups begin the fear the bear, who the places them all in the box and carries them away. Over time, as the pups grow bigger, he eats them one by one until only a single pup remains, Bob.
At the beginning of The Last Wars, Monsoon invades Futago Pass with his kin. He sends his kin off ahead, staying behind until his remaining kin return in retreat to him. He berates his kin for retreating; smacking and insulting them. Then he decides to lead the attack on the dogs himself.
When he finds the dogs he soon begins to shout out at Gin, who is unable to understand the language of bears. Though none of the dogs can understand him, he swears that he will reclaim this land. However he is forced to go back into the trees to hide when Hidetoshi and Daisuke appear in a helicopter. However, once the two men leave he makes himself known again with his kin.
Soon after he is attacked by Gin, who tries to act like a decoy so the other soldiers can help the women and children escape. Seeing Gin charge towards him, he instinctively covers his eyes, as the genetic memory of Akakabuto losing his eye to Akatora flows through him. In defense he swings up his left arm to block Gin's battouga, and tosses the dog aside. The other soldiers follow in pursuit of attack, and Monsoon lashes out at them all, turning it into a sea of blood. However, in this assault only one of the dogs Jaguar is killed. Quickly, Monsoon starts to target Gin again, only to be led by Gin away from the other soldiers, and further into the forest.
Monsoon follows him to the outer edge of the forest, where a large cliff looms. Gin attempts to attack Monsoon in hopes of making him fall, but as he attacks, Hiro charges in only to be crushed under Monsoon's large paw.
Monsoon, realizing what just happened, tears his claws out of Hiro's back and orders his kin to attack Gin again. Gin is wounded by the bears as Monsoon sits back to watch, but upon seeing one of his kin accidently strike himself in an attempt to hit Gin, Monsoon charges in to attack the blind dog, but ultimately strikes Hiro again as he dives over Gin to protect him. The blow sends both Hiro and Gin into the river below. Monsoon celebrates his victory by throwing down several large rocks into the water and roaring.
Monsoon returns to the main battlefield where he orders the elder dogs who killed his father to come forward. Bob relays the message to the Ou army who inform him that most of those dogs are long dead. Monsoon demands to see John, as he loathes him the most and even fears him somewhat.
Tesshin tells Bob that John has been gone a long time, to which Monsoon recovers from his fear and lunges at the dogs, targeting Musashi. However, Kurotora gets in the way and is struck instead, leaving him badly injured. Jerome attacks Monsoon but is crushed under the bear's foot, prompting an attack from Musashi, who is impaled on his claws. Monsoon releases the two dogs, killing Musashi and leaving Jerome badly injured. He and his kin then mercilessly attack the surviving dogs.
The Koga elder returns with his two followers and attempt the attack the giant bear, but are easily struck and killed by the bear. Every single one of the Ou dogs are injured and unable to move, leaving Monsoon to roar out his victory at the fallen paradise.
Monsoon soon spots his kin trying to corner a small dog by some rocks, and tells them not to kill it, as it would be more fun to keep them all alive to eat later. He has built a makeshift dungeon similar to Gajou and has placed all the dogs, both dead and alive, inside as prisoners.
Monsoon orders his followers to guard the prison whilst he sends Bob to capture those who have escaped. Upon returning to the local area, he notices that the bears guarding the prison have vanished and punishes Bob for letting it happen by scratching at his side.
Monsoon lets him live with slight injuries and sends him on his way. Later on, Bob discovers Kenshin being surrounded by bears. Although upset that he has to do this, he calls for Monsoon to kill the intruders, and the giant bear tears down the forest to charge at Kenshin.
Kenshin is ready to fight and attacks Monsoon, biting his nose and evading the oncoming attack. Monsoon is left with a bleeding nose and is very angry as Kenshin attacks again, using his agility to evade attacks.
Monsoon turns his attention to Hiromitsu and Fuyuoni, and successfully crushes them under his enormous paw, killing them instantly. Distracted, Kenshin is slashed by the bear, leaving him mortally wounded and unresponsive despite being conscious. Monsoon then gives the remaining dogs an ultimatum: they can live freely as long as they produce children for Monsoon to eat on a regular basis. Bob relays this to the dogs, and Zion protests this, speaking bear language which confuses both Bob and the bears.
Monsoon gives Bob more orders, but is once again shouted at by Zion. In anger, Monsoon pounces towards the dogs when they are distracted by the death of Kenshin. He slams his paw down on Unsai, but misses as the dog went between his fingers instead. In a brief moment, Unsai and the others quickly flee, aside from Sirius who talks to Bob with Zion. Monsoon looks at Sirius, and remembers how a young Gin attacked John who killed bear cubs. Monsoon swipes his kin away from the dogs when they try to attack, and allows them to take the bodies of Fuyuki and Hiromitsu away, not attacking them as they go. Confused and angered by his own actions, Monsoon roars loudly.
Shortly afterwards, a storm begins to stir. As it rains, Monsoon sends his kin to check on the prison, only to find that all of the dogs have escaped. Monsoon flies into a rage and attacks his own brothers, Bob tries to calm him down to no avail. As punishment for his failure, Monsoon orders Bob to eat the rotting corpses of three dogs.
Monsoon is resting on top of the hill where Kenshin was killed. Bob is shivering as he approaches Monsoon, and the other dogs hear a scream from their position. Monsoon pick Bob up and roars loudly at him. Monsoon lifts his claw up and impales Bob through the bottom jaw, letting him hang for a moment before the bear drops him and slams his paw down on his head.
Bob wriggles free and Monsoon gives him one last chance or he'll be eaten. When Bob leaves his presence, Monsoon hides among the trees to rest and wait. As he does so, Sirius unknowingly runs onto his back, startling the giant bear. In a fit of rage, Monsoon tries to slash his claws at Sirius, who only came to talk but they can't understand each other and Sirius is cut across his cheek. As Monsoon hesitates slightly, remembering a time when a young Gin saved him and seeing how Sirius looks just like him, Akame leaps onto the bear with his weapon and jumps off again before he is hit. However, Monsoon is quick and before Akame lands on the ground, Monsoon deals a devastating blow to Akame's head, giving him three scars and taking his right eye out.
Before any more blood is shed, the dogs try to talk to the bears, with Shion and Bob translating. Bob relays the message from Ou to Monsoon about how he will die like his father, which enrages Monsoon, causing him to attack Bob. Akame uses his scythe to protect Bob, cutting off one of Monsoon's fingers. Outraged, Monsoon asks Akame if he is a pet dog, as he fears them and their human owners with guns. Orion tells Monsoon that they are all pets, which worries the bears. Bob begins to laugh at Monsoon, which causes the bear to lash out in anger for his humiliation and smash his paws on the ground where Bob stood.
Bob is pulled to safety by Sirius and Yamabiko, narrowly missing Monsoon's claws. The impact on the ground further causing pain to Monsoon's paw. Fearing the implication that they are pet dogs, Monsoon decides to try and retreat but is attacked by Akame. He evades the attack from the weapon and skids a few feet back. At that time, he looks back in horror as the Ou army are charging towards him.
With the dogs attacking from behind him, Monsoon picks up the smell of their collars, coming to the conclusion they are pets, which makes him nervous. The smaller bears want to fight and eat as many as they can, to which Monsoon agrees to let them do. The closer the dogs get, the more nervous Monsoon becomes. Monsoon is distracted by his fears from the scent of the collars. Akame takes advantage of this and leaps at Monsoon with the sickle. He slashes Monsoon's eye, and he screams out in pain.
Monsoon lashes out at the dogs as his left eye has been taken out by the sickle. In the fray, the pet dogs attack the bears as Monsoon tries to attack Akame, missing due the ninja dogs swift movements and Monsoon's poor visibility. As he attacks, Orion, Bon and Andy leap onto him and begin their assault.
The sickle is passed from dog to dog as they attack, cutting into Monsoon's stomach and legs, but barely making a mark due to his thick skin. The sickle is eventually stuck into his side, and his finger is cut off. Sirius, who has seen enough fighting, takes the sickle and runs away with it. Monsoon slashes at Unsai, badly injuring him. With the sickle gone, Monsoon turns more violent and nearly kills most of the dogs. Sirius throws the sickle away and returns to try and talk to Monsoon with Shion. Despite Sirius trying to talk sense into Monsoon, he is shocked to still hear that the bears see the dogs as food.
Monsoon continues to chase Orion into the woods, when he comes out he sees Orion coming at him with the Battōga and blocks the attack with his arm. Then, still continues with his pursuit of the red akita and when Sirius tries to reason with Monsoon he still refuses to listen and comes to attack Sirius.
He lands his claws in front of Sirius and pauses at the sight of hearing the sound of guns and some of his kin already dead. Then, he and the rest of his kin begin to flee for their lives with Monsoon taking a different route.
Monsoon as he was continuing his escape, he was still under the shock that the humans came to the dogs rescue. He did his best to tend to his wounds unknown that Kurotora and his group of dogs were prepared to ambush him.
As Monsoon, he comes across Kurotora and his group of dogs. While acting as a decoy Kagetora challenges Monsoon with the Kai Ken telling that his uncle was the one responsible for taking Monsoon's father's eye while sacrificing himself to do it. That he will do the same and Monsoon has his right eye bitten by the Kai Ken and all he does is sway Kage away, still running for his life to the top of paradise.
Before Monsoon can rally his kin to fight back, the hunters arrive and slaughter every single one. Monsoon, hiding in the forest, hears the cries for help from them but ignores them and walks away, deeper into the trees.
He makes back to his territory in the Shirakami Mountains, but his hatred for the Ohu dogs is still there. As he takes a drink from a waterfall, he soon notices a smell and inspects the waterfall by placing his paw into the falls. As soon as he gets his nose and head through the water, he finds Sirius and Shion. Enraged that they were in his territory, Monsoon goes into a frenzy trying to catch them. As Sirius and Shion made their way, climbing up the falls, Monsoon throws rocks at them, saying that his head is exploding just from looking at them.
Monsoon lashes out at Sirius and Shion again, destroying most of the forest in the process. Monsoon is refusing to listen to the dogs. Shion tries to talk him out of revenge but it was no use, because he tells them that his only goal was to eat all the dogs. He gives them another condition; that if they give up their friends as food, then he won't kill the dogs at random; but says he'll never negotiate with them and leaves.
Shortly after a while, Monsoon notices more dogs and humans in his territory, knowing that he doesn't have anywhere else to run, he decides to kill the pet dogs. Monsoon ambushes them killing, one of hunting dogs.
Horrified at what Monsoon had done, he is told by Shion that the humans will have their revenge and that his home will become his grave. But he says that he knows that, and that's why he has to leave no trace of the hunting dogs and demands that the two of them hand over Bell, but they refuse to, while Monsoon continues to look for them.
Then, Monsoon is attacked by Gennai but Monsoon rolls onto his back throwing him off, but during the fight, Monsoon starts to shiver with excitement and shows curiosity towards Gennai. He sends Gennai flying, but when he comes to Sirius, he sees him cry tears of regret and slams his paw on Sirius, knocking him out. With that, he leaves, but also swats Akakama away after an attack from him.
During the night, they he comes across a mother bear and her cub. He instantly kills the mother bear which causes her scream to be heard by Sirius and Shion. He gets asks why did he kill Chibi's mother because the cub wasn't of his bloodline. Monsoon threatens to eat the cub because all he was nothing but food. Then, he feels Sirius leaping on the bear's back trying to get Monsoon to let the cub go. But he gets thrown off but doesn't get flatten by the bear and lets the cub go. After seeing Rigel and the Kamakiri brothers coming Monsoon starts to get angry himself and despite Shion's best to calm him down the bear flew into a rage but they escape with the cub into tow.
When winter arrives, the Ou army begin their final fight with Monsoon. Orion, using his sickle and newly gained ninja techniques, manages to do some severe damage. Monsoon panics and tries to flee, with an injured Sirius in tow, but is cut off by the ocean. Orion quickly catches up and chases the bear into the water, managing to get his sickle into Monsoon's throat, slitting it open. Monsoon dies from blood loss in the sea, finally ending his reign of terror over Ou.