Lydia is a russian German Sheperd who was first sided with the Russian dogs and so, an enemy of Ohu but then joined Weed's army and became Jerome's mate, giving him six puppies. Her brother is Maxim and her father a German Sheperd who sent the dogs to Hokkaido.

Born in Russia, Lydia was a soldier dog who, along her brother Maxim and other German Sheperds, war trained, swam to Hokkaido to take it over. She ambushed Jerome, who was attacked and defeated by another russian German Sheperd, Victor.She tried to know from him where Hakuro was but Jerome tricked her into believing that he was too wounded to speak. Lydia thinks he wouldn't go far so wounded and so, she doesn't keep an eye on him, with the result of Jerome escaping. She is able to find him again where she tells him why she and the other German Sheperds are invading Hokkaido. Jerome tells her that in Ohu dogs can live peacefully and she could join but Lydia refuses, still loyal to the invading plan. Once Hakuro is killed and Jerome is hostage again, she's the one who tells the group to spare his life, since they would need him alive.

Lydia starts feeling something for Jerome, she and her brother aid Jerome and are soon visited by Akame who offers Lydia and Maxim a place in the Ohu army. Tesshin brings back both Lydia and Jerome in Ohu. She fights alongside the Ohu army but is defeated by Bozlef but is saved by her brother Maxim. She and the other injured dogs are healed by Daisuke and Hidetoshi when Weed and the reinforcements finish off the Russians invaders.

At the end of the manga, she and Jerome become parents of six puppies and, in GDW:O she is still alive, along her mate and puppies.

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In The Last Wars, Lydia was killed by Moonsoon, while she attacked him, trying to protect her children and friends. He slashed her on the back and she didn't survive the wound, dying alonside three of her pups.