A Geisha and a swordswoman, Makie was enlisted by Anotsu to kill Manji. A powerful fighter but always reluctant to strike the killing blow Makie fought Manji twice. The first time losing pathetically. Her mission was supposed to be to bring Anotsu Manji's head. She set out to do it the second time and she would've done it had it not been for Rin. She convinced Makie to spare his life and Makie then instructed Manji to watch over Rin always. So far as I've read, she's been the only one good enough to defeat Manji.
YAOBIKUNI
Yaobikuni, whose name means "the nun of 800 years" is immortal just like Manji. In fact she's the one who stuffed him full of the sacred blood worms and pointed Rin towards him. She will be immortal until she has saved the souls of all the sinners in Japan.
MACHI
Machi is Manji's little sister. When she witnessed the killing of her husband by Manji, she regressed into the mental state of a child. Shido kidnapped Machi and forced Manji into a duel. Manji however wanted to give up the sword and said he wouldn't fight. Shido agreed to let Machi go but then sliced her to pieces as she ran to Manji. One (if not) the saddest moments in Blade history.
KUROI SABATO
Kuroi is the man that Rin hates even more than Anotsu. He was the one that actually killed her father. For 2 years, he sent her love poems, hoping one day to once again meet with her. The day came and when his shoulders were revealed it turned out he had stuffed heads on them. One of his former wife and one of Rin's mother. His wish was to remove his former wives head and put Rin's head where hers once was, so that mother and daughter could be together again. Distraught and knowing she couldn't defeat him, she agreed to kill herself if he would follow. Sabato agreed, and Rin would've gone through with it had Manji not killed him on the spot.
SAITO TATSUMASA
A Officer, Saito was Machie's husband. Going home drunk, he was summoned by some other officers saying they were finally catching up to the man who had killed many of their men. Saito confronted Manji, telling him his name which sounded familiar to Manji but he couldn't quite place it. He only remembered who he was when it was too late and Saito was going to strike him down. Having no other choice, Manji killed him.
SORI
A Shogun Ninja, he had given up his former life to work on his "sword painting". When Rin came asking for help, he declined saying his blade wasn't good enough to avenge the death of his friend Asano. Manji didn't buy it and told him off, and Sori fessed up. He just didn't want to fight and risk dying. He did come through for Rin in the end.
HAGE
One of Anotsu's followers, he thought he could take over Sabato's place as right hand man if he defeated Rin (who he thought was the one who had killed Sabato). His plan almost succeeded but his life came to an end at the hands of Sori.
MAGATSU-TAITO
Another one of Anotsu's followers, his sister was killed unjustly by a samurai. He was w/ Anotsu when they showed up at Rin's on the day of her birthday. That day all the swords were stolen, including a treasured Chinese sword. When Rin came upon him 2 years later she offered him 30 Ryo for the sword. He declined but later Manji won it from him in a fight.
SHIZUMI-EIKU
An immortal like Manji himself, he asked that Manji join him so that they could bring Anotsu down. He believed that people are nothing but worms and almost killed Manji with a deadly poison. He kidnapped Rin and when Manji came looking for her, let himself be killed because after 200 years, he had accomplished nothing.