Weed is a brave dog and a strong fighter, just like his father, Gin. Weed believes that enemies can change their ways and almost always gives them a second chance, which is why he surpassed Gin, whom he gave his leadership to. He gets along well with others and makes many new friends during his adventures. He is usually very friendly and playful, though he can be very serious if he needs to be, especially during battles. Weed is often refered to a 'bear hound' because Gin and Riki of Ohu were before they fought Akakabuto. Weed has half the blood of a bear hound and was never trained in the way Gin, Riki and Shiro were.
Weed is a Kishu/Akita mix with tora-ge markings and blue eyes. In the manga, his eyes look more silver than blue. On his father's side, everyone had brown eyes, and his mother, Sakura, has always had blue eyes. And as she's a Kishu mix, the other mix can be a breed with natural blue eyes.
In the manga, Teru was beaten up badly by his father because another dog had stole their food. When Teru was about to get another beating, Kyoushiro shows up and attacks his father. Weed manages to stop Kyoushiro from killing Teru's Father but Teru refuses to see his father as a parent role model and joins Kyoushiro's pack and get a new name; Kōta. When Thunder and Lector showed up, they took Kōta hostage to bring Kyoushiro in. The fight breaks lose and Kōta is saved but his father was fatally wounded. Before his father died, he begs for Kōta's forgiveness which Kōta then gives him. Thanks to his father's change, Kyoushiro gave Kōta back the name his father gave him; Teru.
Teru follows along with Kyoushiro as he joins Weed. Though Teru is a scared little puppy, he has shown some bravery at some occasions like at one time; when he saw Weed who tried to show respect had been kicked by the disgusted Kamakiri, he attacked the old Irish Wolfhound but he got himself injured as well. Despite his injury, he had also defended Reika from getting mauled by Kamakiri's minions while the pack were fighting. Fortunately, both Weed's and Kamakiri's pack had retreated from Ron's warning barks before the hunters could shoot them, Teru was also rescued by the German Shepherd Ron who had brought him back and joined Weed's pack as well. In the end, he was left with Chourou together with the rest of the pups as Weed would not risk the second generations' lives.
In Hokkaido arc, when Victor attacks Hokkaido, Kyoushiro rushes to get help from the Kogas and meets the now grown up Teru who has been taught all sorts of ninja techniques. And after Kyoushiro had a talk with Chourou, Teru and the other grown-up puppies join in with Kyoushiro to fight Victor in Hokkaido. Teru, Kyoushiro and other Junior Ninja dogs were also taken captive along with the Ohu army at the gorge by Victor and the Russian Army Dogs. On the following days, Teru was also seen fighting alongside with the Ohu army in the gorge. However, Teru had got himself wounded by Victor when he tried to protect Gin by shielding his body.
Fortunately, after Weed and his reinforcements turned up in time to help Gin and the Ohu army; Teru, Musashi and Jaguar had been taken to the vet by the humans Daisuke and Hidetoshi while his pack had stayed behind to be nursed back to health. A few days later, when they got better; he, Musashi and Jaguar had been let out by Daisuke and Hidetoshi back to the wild.
In the anime, Teru was a little pup who was beaten by his father. When Kyoushiro and his pack save him, he told them to kill his father, but Weed interferes. He forgave his father when he died after a fight with Thunder and Lector to protect him. He cried about his father's death even though he hated him before. Teru and the other puppies follow Weed until Weed decides to leave them in Koga. After hearing this from Kyoushiro, Teru then comes to the Weed, telling him that he wants to go with him and die for a reason. But Weed tells him that it would be better to live than to die. Later, he and the other puppies stayed in Koga territory while the others went off to war. After that, Teru and the other puppies were never seen again.