There's three major parties (in addition to Rin and Manji).
The school where anything goes. Leader: Kagehisa Anotsu. They'd agreed to leave Edo. But what they actually did was send a decoy team away, while four (Anotsu, three others) stormed the Edo castle and are hacking and slashing their way inside.
The leader of the Shogun's Banshu samurai, the Bangashira, and secret leader of the Mugai-ryū and later the Rokki-Dan. The Rokki-dan are a private army divided into six divisions and fall under Kagimura's direct command. They are the successors to the Mugai-ryu and also consist of criminals. Should they fail to destroy the Itto-ryu before Habaki's execution, they will be executed as well.
Hanabusa, the master mind that is pitting the Ittō-ryū against Habaki Kagimura. Would let Rin and Manji live in the hopes that more people die. Wants to get rid of both Ittō-ryū and Habaki Kagimura.
Tried to force Habaki Kagimura while holding his wife hostage. His wife committed suicide, and Habaki is even more determined to go after the Ittō-ryū.
Shira: Member of the Mugai-ryu, a school very similar to the Ittō-ryū. Super sadistic. Last seen alone on the road, killed some of Hanabusa's ninja. Had one hand taken off, sharpened the bones on his arm to be a weapon.
Meguro and Tanpopo (a recurring joke is that Tanpopo's buxomness saves her over and over). Kunoichi of the Rokki-dan. They were students of the art teacher, Master Sori, that Rin stayed with for a while, too. They were spies for Kagimura as members of the Rokki-dan.
Baro (Shida) Sukezane Itto Ryu, lover of Tsukiji. Scar across nose.
Sadamasa had memories of Shida Sukezane and Tsukiji. Commanded the death of Sukezane.
Shira and Renzo (son of an Itto Ryu that Rin hired Manji to kill) tied Rin under water to force Manji to choose to save her and freeze/drown himself, or let her die.
Meguro and Tanpopo arrive and save (the pokey haired Itto Ryu guy from Shira) and Rin from the water. Manji and the pokey haired guy barely defeat Shira, leaving him in the snow. Later, wild dogs tear Shira apart in front of Renzo. Renzo returns to the cabin where everyone is recuperating. Renzo threatens to slice the arms off of Manji, but is told to learn more about his father before acting.
Habaki learns that Anotsu Kagehisa and three other Itto Ryu infiltrated Edo castle and killed over a hundred Banshi. He's determined to get vengance.
Manji goes with Rin (carrying her sometimes, because she's still got frostbite) to Hitachi to catch Anotsu.
Meanwhile, Anotsu is delayed because every available horse for hire has been killed. He hopes Abayama can stay alive for him.
Meanwhile, at Abayama's group, Koji, an old man with glasses, splits off from them, to lead some of Kagimura's men, the Hana-gumi, (and daughter, Soma Ryō) into a trap in the woods on the hillside. (There are pots that emit carbonic acid gas.) Soma defeats Koji and is the sole survivor of the encounter.
On her way back, Mitake tries to take her to safety on horseback, away from the upcoming battle. They meet Giichi (bald with circular glasses) and Hyakurin on the way. They agree to watch Soma.
Kagimura sends three on horseback to try and delay (or fight) Abayama's remaining group. Abayama prepares to fight, but all the other Ittō-ryū “quit” the Ittō-ryū in order to kidnap Abayama to safety (to preserve the Ittō-ryū) and to take on the three men of Kagimura.
Abayama and his few “kidnappers” debate whether they all should have quit and stayed to fight Kagimura's men when Giichi and Hyakurin suddenly appear on horseback. (That's how it ends.)
Abayama Sosuke, despite having only one arm, cuts off Giichi's ear (Giichi of the Mugai Ryu), making him lose and break his glasses. Abayama had lost and arm, and in its place are two chains with weights. Giichi sacrifices his leg (used to block the chains) to get close to Sosuke and pummel him nearly to death.
Hyakurin kills some Itto-ryu with her forearm-mounted crossbow.
A couple of Ittō-ryū are killed by the giant white guy (sent by Kagimura) who wears metal armor and wields huge heavy oar weapons. Two were named Maira and Satake.
Ittō-ryū Kurehiro (German speaking?) and Katsumata fights another German speaking fighter sent by Kagimura. They both lose.
The battle between the sumo-wrestler sized Ittō-ryū and the little frog-like guy with the venom spitting weapon ends in a draw. They both die.
As Giichi leaves Sosuke, he notes that while they live, Sosuke and Anotsu still have the Ittō-ryū name. But Giichi has nothing, but he can't let himself get killed (for Hyakurin's sake).
Flashback to when Kagehisa Anotsu's grandfather (Saburō) led the Ittō-ryū and threatened to kill Kagehisa (because Kagehisa would change the direction of the Ittō-ryū) to Abayama Sosuke. Abayama kills Saburō in response, under the guise that he “requested” it as an unfit leader.
Back in the present, Abayama reclines after being beaten by Giichi, and sees a ghostly darkness, and talks to it as if it were Saburō. He dies.
Giichi catches up with Habaki Kagimura (uninvited), and they tally up that they've killed half the Ittō-ryū. Only Anotsu's Edo party remains, and Habiki heads to the port of Nakaminato. At the port, Habaki orders the killing of every single port man as a preventative measure against Anotsu.
They're outmatched by Makie Otono-Tachibana, (Anotsu's female companion), on one of the boats. She has tuberculosis. (Habaki lies to the local constables about who did the killing on the boats, blaming the Ittō-ryū.) Makie kills the constables who surround her.
Just before the European Giant, next in line to kill the woman, can kill her, Manji shows up. He gives her “medicine” in the form of an Asaemon pill that she needs since Anotsu wasn't around to do it himself.
Rin shows up to the party by land, just before Anotsu shows up by sea. Anotsu explains his complicated strategy, and vows to kill Kagimura that day. Kagimura orders the Eurpean Giant to kill Rin, Manji and Anotsu's girlfriend. A two-page spread of a fight, a scene of tree branches, and then… Rin's(?) crawling along the street, about to die, and unexpectedly gets picked up on horseback by Taito Magatsu (with the spikey hair and face cloth).
Manji has trouble fighting the well-armored European giant, and Rin tries to help by doing her dagger-throwing Swallow something attack at him from behind. He deflects the attack and comments about their “two vs. one” strategy. “Hmf. So it's my fate to destroy such a young girl?”
All fighting, all the time. The fights are interleaved.
Habaki Kagimura and Anotsu Kagehisa fight amonst Mon Gates on a hillside. Anotsu loses his heavy weapon, and uses is sword. Eventually, they both lose their weapons, and in hand-to-hand combat, they fall down the mountainside. No telling how either one fares.
Manji fights the European Giant. His arm gets torn off. Rin's out finding whale oil an flint. Manji's body is torn in half. Rin covers it, and stalls long enough for Manji to splice back together. Rin sliced her wrist to cause bleeding that'd convince the giant it was Manji bleeding and dying. Manji manages to slice the giant's arm off, and graft it to his own body. He looks freaky with the one large arm. Rin covers the giant's body in oil and ignites it. After more grueling battle, Manji defeats the giant. Manji tries to save Rin before she bleeds out. She's cold, and he carries her away.
Makie fights more of Habaki's goons. Tarieshin, Mitake and Doma take her on next. Just before Makie can finish off Mitake, he sees Giichi appear behind her, and pleads, “Kill this she-demon!”