Hyakurin(Jpn. - 百琳) is the former deputy leader of the Mugai-ryu in Blade of the Immortal.
Hyakurin, formerly known as O-Hyaku, was the wife of samurai Hayakawa Kakōsai Genkei, who was cruel and abusive. Hyakurin bore him twins, one boy and one girl. Genkei killed the girl when she was born, saying he had no need for a daughter. Their son was found to have the same genetic illness as Genkei and his father before him, and Genkei, assuming Hyakurin would bear him another child, cut him up in front of Hyakurin's eyes when he was eight years old. Hyakurin then killed her husband and was arrested, having had a mental breakdown. She was nearly executed before Habaki Kagimura, accompanied by Giichi, arrived to save her life in return for her fighting skills. She then joined the Mugai-Ryu.
During the story, Hyakurin assists Manji and Rin while still doing her own duties in the Mugai-Ryu. After failing to kill a random enemy (Tamasaki), the enemy returns with reinforcements to interrogate Hyakurin about "who 'Akagi' is". The men end up killing Shinriji during this struggle, and kidnap Hyakurin. Hyakurin is severely tortured and raped for several days before Giichi discovers where she is and saves her life. Hyakurin's fighting skills are dampened, specifically after breaking her arm badly under torture. She also becomes pregnant and nearly aborts the baby, but Giichi stops her, convincing her to keep it and to "consider it our last chance to ever be normal."
Hyakurin continues to help Rin whenever she can, but doesn't do much more intense fighting. In the end of the story she is seen walking with Rin, telling her she's just a kid and doesn't even know what she wants from life yet. She is visibly pregnant and it is assumed she and Giichi will raise the child together.
Hyakurin bleaches her hair as a compulsion to remove bloodstains from it, an urge which began after the death of her son (and the murder of her husband). She often wears a black wig to cover her blonde hair. She also smokes.
She takes Rin under her wing, though still retains her pragmatic attitude in regard to the girl.
Hyakurin's skills lie in stealth and speed rather than sword-skill or strength. She often uses poison darts via her wrist crossbow.
Shinriji and Hyakurin have a close and unusual relationship. Shinriji is very insecure, but idolozes Hyakurin. Hyakurin is loud and never cares what anyone thinks of her, and is particularly harsh to Shinriji. She often attacks and picks on him when he makes mistakes or says something that bothers her. Just before Shinriji's death and Hyakurin's kidnapping, Shinriji attempts to ask Hyakurin to marry him (using very subtle wording) but Hyakurin changes the subject and he recants. During her torture, Hyakurin remembers the first time she met Shinriji and shows that she did care for him (also acknowledging his botched proposal a few days earlier), and likely would have ended up with him had he lived.