The protagonist and Gin's son.
- Beware the Nice Ones: Weed is the most polite and the nicest puppy but if you mess with him, you are seriously in big trouble.
- Call-Back: The part where he gets pissed off at Jerome for killing Thunder and Lector (the foxhound spies in the manga) while they were defenseless is reminiscent of the Nagareboshi Gin episode where John killed two defenseless bear cubs right in front of Gin, which pissed him off. What brings it more home is that even the same dog breeds are used (Gin and Weed = Akita, John and Jerome = German Shepherd).
- Forgotten Fallen Friend: In the anime at least, Weed gets over the death of his mother extremely fast. He's fittingly more heartbroken in the manga, and thinks of her often during his journey.
- Generation Xerox: He's a dead ringer for dear old Dad. They're very similar in personality, as well.
- Glowing Eyes of Doom: When he unleashes his battōga.
- Hair Color Dissonance: He is blue, but this is probably just meant to represent stylized gray.
- Heroic Lineage: Weed comes from a line of badass bearhounds. Because of this, he is a powerful fighter even when he had no experience or training whatsoever and is among the very few dogs who can preform the battōga, which was originally a wolf's attack.
- Heroic Second Wind: He's badly beaten by Hougen at their fight and nearly dies, yet manages to stand up again after being encouraged by the spirits of past Ohu soldiers.
- If You Kill Him, You Will Be Just Like Him: His often-invoked argument to his subordinates.
- Incorruptible Pure Pureness: As Jerome lampshades, "Weed, your spirit is too pure."
- Informed Attribute: He's stated to be "tora-ge" (tiger-striped, i.e. brindle), but much like his father Gin whose stripes disappeared after three episodes, Weed bears no visible stripes. He is also stated (along with his father, older brother, and oldest son) to be silver, despite appearing blue.
- In the Blood: Inherits natural strength from his father the way Gin did from Riki. This includes the ability to do the battōga.
- Intimate Healing: When his group finds him nearly having frozen to death in a river they help him get warm again by making a huddle around him.
- Leitmotif: His acoustic theme during lectures is about the only subtle one in the series.
- Luke, You Are My Father: He tries to tell Gin in the Kaibutsu Arc that he's his son, except "Gin" is actually a identical substitute called Tokimune, and he doesn't have a clue what the puppy is talking about before he dies.
- Meaningful Name: He was named Weed (oddly, by GB, not his mother) as a reminder that he will never be alone, but will always be surrounded by friends like how weeds can be found everywhere.
- Parental Abandonment: Sakura, Weed's mom, dies in the first episode, leaving Weed in the care of some of his father's old friends.
- Passing the Torch: Gin makes Weed the new leader after he's defeated Hougen and given a Rousing Speech about the power of kindness.
- Save the Villain: In the second episode, Weed tries to save Blue from getting hit by a truck. In episode 16, he tries to stop Jerome from killing both of the doberman brothers.
- Stupid Good: He is adamant to Save the Villain no matter how many dogs they kicked. He gets called out on this in-universe more than once, specially after banishing Jerome, to which Kyoshiro chews him out for being too naive and he should accept that taking lives is part of a war. Weed is confident that he's right however, and states that his beliefs won't change even if he should end up alone with them.
- Thou Shalt Not Kill: Somewhat zig-zagged with him as he is willing to kill an enemy in self-defense or otherwise when it's the last way out, but killing someone who's defenseless and/or are pleading for their lives is a major rage point for him, to the point he even refuses to kill the Big Bad when the latter's been wounded so badly he can hardly stand, and lectures his father (who to be fair, was only testing him) and everyone present for wanting to do so.
- Took a Level in Badass: Throughout his series.
- Wise Beyond Their Years: He is supposed to be this, although to most of the audience he can come across as being overly nice to the point where he makes bad decisions, like letting murderous dogs that want to kill him and others live.
- Babies Ever After: With Koyuki at the end of the manga.
- Busman's Holiday: He tried to have a honeymoon vacation with Koyuki but it was interrupted when his close friends brought the news to him about his father fighting Victor in Hokkaido.
- Despair Event Horizon: He loses his composure after being told his father was killed by Sniper/Murder S, causing him to cry heavily before deciding to run alone into Hougen's troops to challenge Murder S to a fight, not caring if he should die doing so (thankfully, he later finds out his dad is alive after all).
- Died in Your Arms Tonight: In the manga, the dying GB asks for Weed to hug him. Needless to say, his wish is fulfilled, and GB dies as Weed is still embracing him in what is a massive Tear Jerker.
- Plot Armor: Near the beginning of the manga, Weed gets shot. A lot (there were at least 34 bullets in him, according to a later scene). Not only is he back on his feet after a few days, but he is also showing absolutely no signs of being shot over thirty freaking times afterwards. Did we already mention that the protagonist in question is a months old puppy? No wonder the anime took this out (though to be fair, the anime did also add in the scene where Weed uses the Battōga on the guard dog despite never having trained and not even knowing what it was).
- You Killed My Father: He's mistakenly told that his father was killed by Sniper/Murder S at one point, to which he becomes livid and runs into Hougen's pack all alone to challenge Sniper/Murder S to a one on one battle. Ultimately he wins as he pushes a badly wounded Murder S onto a highway where he's hit by a truck. (Unfortunately, it's later revealed he survived, but Weed also got to learn that his father wasn't dead after all.)
A powerful ally of Weed.
- Death by Adaptation: Dies in the anime, but is still alive and kicking in the manga.
- Hypercompetent Sidekick: He's one of most competent dogs of Weed's pack until he was banished by his leader after killing Lecter and Thunder. Though in the manga, he came back from his banishment after Murder S' defeat and remains as Weed's hypercompetent sidekick.
- Kick the Son of a Bitch: He mercilessly kills Thunder and Lector after they plan on attempting to murder Weed a third time. Unfortunately, his act of killing them while they're defenseless does not go over well with Weed.
- My Master, Right or Wrong:
- In episode 5 he informs Kaibutsu how wrong the latter was to attack and flee from the humans that had been torturing him for 5 years because "it's a dog's duty to obey his master and endure any pain he should put you through." ...what? Oddly enough he then averts this at the beginning of episode 6 where he "tells" the humans about to land with a helicopter that he won't obey to their cruel ways anymore and that they should stay away, or he'll attack them the minute they set foot on the ground.
- He epitomizes this trope after he accepts Weed as his leader. Even when he kills Thunder and Lector in the anime, he tells Weed that he did it for him, agrees that he did something wrong even though he thought it was right only a few seconds ago, is willfully exiled, and even tells Kyoushiro to go back to Weed when he follows him.
- Suicide Attack: When he and his comrades are fighting Kaibutsu, whose tactic consists of charging him one by one and bite into his chest, where his heart is located. Doing so, Kaibutsu will pull them off, killing them in the process, but not without them using his own force to rip parts of his chest out, leaving more and more access to his heart for the next attacker. By the time it's Jerome's turn, he reaches all the way in to his heart, however, ends up letting go as his injuries are too great. Although the attack does give Weed's group the opportunity to off Kaibutsu themselves, having progressively slowed him down and weakened him.
- 10-Minute Retirement: When he's banished by Weed after he killed the Foxhound Spies, several dogs such as Kyoushiro, George and Ron called it quits and decided to join Jerome. However, they later went back to Weed after Jerome told them off that it wasn't necessary.
- Cowardly Lion: His character arc is learning to be less cowardly and selfish.
- Only Known by Initials: His full name is Great Britain. Of course, nobody ever calls him that.
- Took a Level in Badass: In the manga, he took a huge level of badass when he rips off Hybrid Bear's claw before dying completely.
A young dog that is very powerful for his age. He leads a pack of dogs that were abused by their parents. Weed seeks him out in hopes of getting him to join his pack, but they start off on the wrong foot.
- Abusive Parents: Kyōshirō's main motivation for learning how to fight.
- Fake Defector: He pretended to betray the Ōu Soldiers so that he could inflitrate Gajō to find out about Hougen's plans but it didn't go as planned...
- Heroic Second Wind: When he is fighting Buruge, he appears to be defeated and about to die, but Toube's ghost speaks to him and Kyōshirō finds the strength within to keep fighting.
- Rugged Scar: Is covered with them. How he got them is never told, but one can assume either has been fighting a lot all his life or they're from his father, or both.
- Well-Intentioned Extremist: When he first shows up he makes a living by beating and sometimes killing parents he finds abusing their children, as a payback for having had an abusive father himself.
- Younger Than They Look: Kyōshirō is the same age as Weed, despite looking much older.
- 10-Minute Retirement: Was among the dogs who tried to Join Jerome when he was banished.
A former loner who joins Weed's pack.
- Badass in Distress: The tough-as-nails loner gets captured by Hougen while defending Reika.
- Cruel Mercy: He inflicts one on Kamakiri after defeating him. He lets him live, but without fangs or testicles.
- Groin Attack: His specialty, though he does not do it very much in the Anime.
- You Killed My Father: Happens to poor Hiro when Kamakiri killed his father as a puppy.
- Anthropomorphic Shift: He's one of the main culprits of this in the comedic moments.
- I Have You Now, My Pretty: Hougen takes her hostage in order to blackmail Gin and John into letting themselves get caught (and beaten half to death). Later he tells her he intends to keep her captured because he wants her as his mate and she's gonna give birth to his offspring. Poor Reika is terrified.
The starter-antagonist of the series, he was a tortured lab dog that eventually escaped and went mad.
- Alas, Poor Villain: Was revealed to look and behave like he did because he was tortured for 5 years by humans using him for scientific experiments.
- Animal Testing: His backstory and how he became what he is (just what were they testing on him?)
- Canis Major: According to the guidebook, he weighs at around 1200 pounds.
- Death by Falling Over: He was finally defeated by Weed, Ken and Kagetora who pushed him off the cliff and got himself impaled by a sharp branch from the log in the middle of a waterfall.
- Evil Sounds Deep: Coupled with Guttural Growler, his voice is quite deep and menacing. It might be partially thanks to his mutation.
- Humans Are Bastards: A central theme in his Back Story.
- Impaled with Extreme Prejudice: He finally dies from being impaled by a sharp branch on a log.
- Irony: Kaibutsu, a giant, insane mutant dog is defeated after roughly three episodes. Hougen, a regular Great Dane serves as the Big Bad for the rest of the series.
- Shaped Like Itself: His name means "monster".
A vicious, sociopathic dog who strives to take over Gin's territory through any means necessary. He becomes the main antagonist of the series.
- Cold-Blooded Torture: He tortures Gin and John during their captivity.
- Even Evil Has Loved Ones: For all his evil, he did love his brother Genba, mercy killing him (see below), shedding a tear while doing so.
- From Nobody to Nightmare: He and Genba were just a pair of poor Great Danes which were locked up and abandoned in the run-down kennel. With months of starvation, fighting and cannibalizing other dogs, they later killed their owner and broke free which then later they became the most feared rogue dogs.
- Jerk with a Heart of Jerk: Towards the ending there's a scene where he, Jerome and Reika are being swept through a river. To Jerome's surprise he sees Hougen grab Reika and pull her towards the shore as if he intends to save her, however it turns out he was only going to use her as a stepping object to help himself get out of the water.
- Karmic Death: Killed by lightning at the end of the anime (while shot by a vengeful ex-policeman in the manga).
- Literal Maneater: They flat-out ate their abusive owner before running off into the wild.
- Mercy Kill: When Genba was heavily-wounded, paralyzed and gone insane from the damage by Tesshin (and in the anime's case, Shigure), Hougen had to mercy-kill his own brother by snapping his neck (in the manga, Hougen bit his brother's head and tore his whole brain out).]]
- Nobody Poops: Averted. When he first meets Gin, he kindly introduces himself before abruptly defecating right in front of him. And then he dares Gin to eat his shit.
- Not Quite Dead: Pulls this off WAY too many times. It is rather pitiful that while a gigantic monstrous demon bear is taken down after one hit with a battōga, Hougen doesn't bite it until roughly THREE battōgas and a direct lightning strike.
- Oh, Crap!: The look on his face when he sees Weed performing the battōga attack for the first time.
- Rasputinian Death: To a degree. In both anime and manga, he takes several hits of Weed's Battouga, though thanks to them not being delivered with full force he recovers each time. Even when Weed finally manages a full forced blow to his head which causes his skull to crack, he still manages to stand up after a few moments and climbs all the way to the top of Gajou. It finally takes a well placed lightning bolt (presumably created by the past Ohu soldiers' ghosts) to end him. In the manga, he stands up after the same grievous injury as well, though he's more clearly shown to have completely lost his sanity and is simply having a "death walk" with his last bit of strength, until Shouji appears and blows his brains out.
- You Have Failed Me: He and his allies are not merciful when someone screws up (screwing up here having the meaning of being in any way connected to a bad incident).
Starts of as The Mole of Weeds Group, until he eventually has a change of heart.
A dog fighting champion.
- Snow Means Death: Toube freezes to death after fighting Kamikiri and his pack. The next day, the Ohu soldiers find him... literally frozen to death.
- What the Hell Are You?: Kamikiri and his dogs had nearly beaten him to death and leave his body there. But when Toube gets up, Kamikiri has a look of shock on his face, and he says this almost every word-for-word:Kamikiri: What the hell is he?!
Lector and Thunder
An assassin duo.
An Irish wolfhound who combines his own pack with Hougen's pack.
- But for Me, It Was Tuesday: When Hiro reminds Kamakiri about how the latter killed his father in front of him, the wolfhound merely retorts that he doesn't remember.
- The Dragon: He becomes this to Hougen after Genba's death.
- Karmic Death: He suffers a nasty Groin Attack from Hiro and gets his fangs torn out, leaving him a sobbing and bleeding wreck.
- Meaningful Name: His name means "praying mantis", and his introduction scene is ambushing Rocket while he isn't looking.
- Villainous Breakdown: Castrated and defanged, Kamakiri tries attacking Hiro while the latter is leaving, but since he doesn't have fangs anymore, he only leaves a bloody smear on Hiro's fur. He's left sobbing and howling as the crows move in for the feast.
- Domestic Abuse: It's shown in Ginga Densetsu Weed: Orion that he's been a pretty crappy mate, flat-out mauling his mate in front of their puppies.
- Babies Ever After: With Jerome.
- Tertiary Sexual Characteristics: The markings on her face are in the shape of a heart.
- Aloof Big Brother: He is cynical, sarcastic and aloof, but it's subverted in that he is not an older brother, he is the middle sibling.
- Chuck Cunningham Syndrome: He really should have made a appearance or at least got a mention in the anime to avoid this because his brother is there, leaving his absence unexplained.
- Dog Stereotype: Subverted. He is a feminine looking dog, but is male.
- Lightning Bruiser: He may look weak, but unlike his Great Dane-mix brother Ken, he is not only fast but also has his father's strength.
- Rugged Scar: Is covered with them.
- 10-Minute Retirement: Is among the dogs who attempted to join Jerome after he was banished.
- Why Did It Have to Be Snakes?: His fear of water.