Knowing how strong Kenshin was when he was the Hitokiri Battosai, Jine takes Kaoru hostage in order to fuel Kenshin's anger. The two engage in a fierce battle. However, Jine, believing that Kenshin has not yet regained his former strength, inflicts the Nikaido Heiho "Shin no Ippo" on Kaoru, causing her to stop breathing. With only two minutes until Kaoru dies of asphyxiation - Kenshin's anger reaches its peak.

After defeating Arundo Akamatsu, Kenshin returns to the Kamiya Dojo and sees Hajime Saito. Hajime had introduced himself to Kaoru and Yahiko as Goro Fujita, the police officer, and they had invited him into the Dojo without any suspicion. Hajime criticizes Kenshin and the others for their naivety. Over the past ten years that Kenshin had washed his hands of manslaying, Hajime had honed his killing intent and skills as a hitman, and now Hajime's ferocity was aimed at them.

At last, Kenshin faces off against Aoshi Shinomori, the head of the Oniwaban Group. In the Bakumatsu Era, the battle-obsessed "Oniwaban group" lost their meaning of existence after surrendering the castle they served without even being able to fight. Aoshi is unable to bear this regret and is in earnest pursuit of the title of the strongest warrior. As a former Revolutionary warrior, Kenshin cannot tolerate conflict without morality. Two men who made killing their profession in the Bakumatsu Era clash against one another, putting their pride on the line.

In order to kill Kenshin, Kanryu uses his Gatling gun and rains a flurry of bullets at him, uncaring that the Oniwaban Group that was under his command would also be hit by this attack. In the face of this evil act, the Oniwaban Group make full use of their individual abilities to counter the Gatling gun. At this moment, theirs and Kenshin's purpose become one. Kenshin and the Oniwaban group team up to challenge the overwhelming power of a modern weapon.

The person who had sent Hajime to face Kenshin was none other than the Head of the Home Ministry, former Satsuma Domain Revolutionary warrior, Toshimichi Okubo. He asks Kenshin to go to Kyoto to stop the secret plans of a man who claims to be the legitimate successor of the Hitokiri Battosai. However, that man was supposed to have been killed 10 years ago by his own comrades in the government, as they regarded him as a threat. Receiving this request to conduct an assassination, what will Kenshin's answer be...?

Making the decision to fight against Shishio, Kenshin leaves Kamiya Dojo and sets off for Kyoto via the Tokaido by himself. Meanwhile, Sanosuke and Yahiko attempt to go to Kyoto to follow Kenshin.

Kenshin confronts Sanosuke, who wields the giant Zanbato with ease. However, Sanosuke shows his incredible durability after withstanding a strike from Kenshin with ease. This leads Kenshin to instead launch a barrage of blows at him, and Sanosuke falls to the ground. For a moment it looked as if victory has been decided. However, while Sanosuke is in a daze, he recalls the reason for his obsession with victory, his past from ten years ago when he was in the Sekiho Army...

Kenshin, Sanosuke, and Yahiko scramble to take back Megumi from the Kanryu residence. They are confronted by Han'nya, a spy of the Oniwaban Group. He trifles Kenshin with his martial arts skills and his "Arm-extension Spell", but Kenshin successfully conquers him when he uncovers the secret of the technique during the fight. Just when it looked like the battle was up, Han'nya removes his mask and reveals his startling true face.

Yutaro sustains a heavy injury from Raijuta's sword, and it is so severe that he will never be able to swing a sword with that arm ever again. Although Yahiko was constantly disagreeing with Yutaro until now, he understood very well what swordsmanship meant to him. He takes Yutaro's hand and leads him out of the medical room, so they could witness the final battle between Kenshin and Raijuta. Deep in the night on a woodland path, Kenshin and Raijuta's duel begins.

Kenshin receives a request from the police chief, asking for his help to take down "Kurogasa," a serial killer who has been repeatedly targeting former Revolutionary warriors. Kenshin and Sanosuke go to escort Jusanro Tani, who received a letter containing a death threat. As warned in the letter, at 1:00 a.m. sharp, Kurogasa appears. His true identity was Jine Udo, a vagabond slayer who had made a name for himself in the assassination business since the Bakumatsu Era.

Kenshin sees a dream recalling the Shinsengumi, who he faced off against back when he was a Revolutionary warrior. The Shinsengumi was a group of highly skilled swordsmen who he fought on equal footing back when he was the Hitokiri Battosai. He feels unsettled and ponders why he is suddenly remembering them. As the tension persists, a mysterious man with very unique-looking eyes pays a visit to the Kamiya Dojo while Kenshin, Kaoru, and Yahiko are not home. When he meets Sanosuke, who just happened to be at the Dojo, he claims that he is Goro Fujita, a medicine seller, but...

Kenshin, Kaoru, and Yahiko visit Akabeko, a beef hot-pot restaurant, where a group of democratic rights activists gets into a heated argument. One of them throws a bottle of sake, and it hits Kenshin, causing a commotion. Sanosuke Sagara, who happened to be in the store during the quarrel, stood up and blew away the activists with a single flick to the forehead. Seeing Kenshin's strength, Sanosuke's curiosity is roused and he asks, "You wanna buy a fight from me?"

Sanosuke's friend has died from an opium overdose. However, Kenshin and Sanosuke are perplexed at how he even got his hands on the drug, since opium is banned and too expensive for the average person to afford. Then a mysterious woman, Megumi Takani, appears before them. Kenshin and the others fight off Kanryu Takeda's private army who is trying to capture Megumi. However, Megumi is carrying opium...

Hyottoko, a member of the Oniwaban group, raids Kamiya Dojo, where Megumi is hiding. He unleashes his special attack "Fire Breath," in which he breathes fire from his mouth, onto Kenshin and Sanosuke. Anticipating the defeat of Kenshin and the others at the appearance of the powerful middle-ranked spy, Megumi tries to flee the scene, but Kaoru stops her and says "He's fighting for you," telling her to believe in Kenshin's strength.

Kenshin defeats Senkaku and finally faces off against Shishio. However, Shishio expresses his disappointment at Kenshin's policy of refusing to kill and lets his close associate, Sojiro Seta, deal with Kenshin. He leaves the village with another associate of his, Yumi Komagata. To continue his pursuit of Shishio, Kenshin faces off with Sojiro and exchanges blows of Battojutsu, which can make or break the fight's outcome. It is a battle of divine speed from both sides...

Seeking a replacement for his broken sakabato, Kenshin visits Seiku, the son of highly honored swordsmith Shakku Arai, only to learn that he has quit making swords. Respecting Seiku’s philosophy of peace, Kenshin gives up his request for a new blade. Meanwhile, Ten Swords member Hoji Sadojima reports to Shishio on Kenshin’s movements.

Known as “the Sword Hunter” in the Ten Swords organization, Cho is adept at maneuvering a variety of different and unique swords. As for Kenshin, he continues to risk his life and fight for peace in the new era and to save Seiku’s son, Iori, even though he’s forced to fight with a broken sakabato.

Going back in time, the 4th year of Keio. Kenshin is suffering from a high fever in the main hall of a desolate shrine. Kenshin falls asleep and when he awakens, he finds himself being nursed back to health by former private detective Giichi and his wife Satsuki in their home.

Hoji plans an attack of Aoiya at night using a secret unit, the Owl Clan, in order to capture Okina and catch a hint of Kenshin's whereabouts, but instead the Owl Clan were the ones defeated. Okina challenges Aoshi to a battle via a member of the clan whom he sent back to Shishio's location.

Kenshin undergoes training so that he can learn the ultimate technique. He barely manages to get in a hit against Seijuro in a bout, where he then learns "Kuzuryuusen,"a powerful technique that launches nine slashes at the same time. Kenshin learns to see through Seijuro's swift sword movements and masters "Kuzuryuusen" by looking at it only once. However, the technique was only born out of the process of passing down the ultimate technique, "Amakakeru Ryuu no Hirameki" of Hiten Mitsurugi-ryu.

Shishio's underlings inconspicuously prepare for their battle plan when patrols arrive causing them to retreat.

It is now midnight. Goichi and the others start moving as it is time to put the Great Kyoto Fire plan into action, when they witness Shishio's other underlings being chased by the police. Henya is annoyed that the fires haven't started on time. Meanwhile, an order is dispatched to the Ten Swords, and they start moving upon hearing their orders. Behind the scenes, Kenshin and the rest arrive at Osaka Bay only to come across something.

The engine room of Rengoku. Hoji manages to catch the explosives and prevents the room from blowing up. However, Sanosuke delivers the Mastery of Two Layers to the ship's Kingston valve, flooding the perimeter. Meanwhile, Usui reveals himself to Kaoru, Yahiko, and Misao as Arato faces off against Kamatari and Henya. Goichi begs for Megumi's help at her clinic to heal Tokuji, his younger brother. As these passions clash with each other in all places of Kyoto, a small, over-looked fire begins to flare up.

In Kyoto, Kaoru quickly notices something strange with Misao, as Misao comes back to the location where a fire was put out. At Megumi's clinic, Omi awakens, bringing tears of relief to Juro. Meanwhile, a black tag is put on Tokuji's toe to mark that he is dead. Kenshin and the others come back to Aoiya, where they learn from Omasu that Okina has woken up.

The pursuers from the Oniwaban Group haven't made an appearance for over a week, and during this time Megumi familiarized herself with the Kamiya Dojo group. Sanosuke, however, was still unsettled and feeling frustrated knowing that Megumi was the one who made the opium that caused his friend's death. Then one day, Megumi suddenly disappears. In a letter they found from her, it stated that she had left of her own volition, but Kenshin and the others found this to be unnatural. They decide to head to Kanryu Takeda's residence, the man who was sending spies after her.