Battered, weary, and unable to touch his mentor Hiko Seijūrō XIII, even at his level of skill, Kenshin is granted the final window of opportunity to prove to his master his worth to learn the ultimate technique of Hiten Mitsurugi-ryū. As the following days of his training pass, eventually, life comes to gather all summoned to the call of destiny in Kyoto, good and evil. With the true battle only days ahead, there is no turning back now- Will Kenshin be able to master the ultimate technique?
Under an early morning, a country road turns into the sight of a bloody massacre. Strewn about are a caravan of slave traders, and lastly, three young women and a boy remain. The young boy, wishing to protect the young women, picks up a sword and dashes at the bandits, but is pulled back. Under their safety, they huddle over him, and pray for them to spare his life. Crying, they whisper to him how he must live, and that he has much to live for. One by one, the young women do all they can, but are also slain. As the young boy remains, traumatized, a bandit desires to end his misery, but appearing out of the dark, a man in a white cape slays his gang. Desiring to know who he is, the caped man refuses to give his name to someone soon to die. Charging headfirst, the caped man then immediately slays him.
Wiping the blood off of his sword, the caped man tells the young boy, that even if he hated or loved them, the dead cannot be brought back to life. Walking away, he departs with words to look on the brighter side of things, and to go to the nearby village for their help.
As the morning sun rises, the caped man asks a brewery if a child has been seen or found. Without confirmation, he is saddened, and departs along the road decorated with Jizo. Weary of the world, he concludes that the grief must have been too great for the young boy, and that he committed suicide. Though sorrowful, the bitterness remains for him to know that in life, such things happen everyday. Though the caped man wields a sword of such a style to protect people, he is disappointed and doubtful, not even able of fulfilling his sworn duty. As all he can do now is to bury the dead, he makes his way to the scene of the crime- And as the morning sun hits the hill before him, he is in surprise.
The barren hill lit by the morning sun, lay marked with graves. The young boy that survived, properly dug graves for all, slave trader or bandit. Asking the young boy if they were his family, he mentions that his mother and father died a long time ago, succumbed to the disease of cholera. The three young women that gave their lives to protect him, Kasumi, Akane, and Sakura, he wished to protect them, left alive as the only male, even at the expense of his own life. Wishing he had more beautiful things to mark their graves, only with stones he found, the caped man opens his jug. The caped man states that one mustn't live life without knowing the taste of good sake, pouring his sake out onto their graves as tribute for what they have done for the young boy. Wishing to know the child's name, his name is Shinta, but the caped man decrees that is too soft of a name for a swordsman- He shall now be named Kenshin, and the caped man promises to give the young boy his best training under his tutelage, taking him under his care.
In the present day, Kenshin struggles to properly land even a single blow on Hiko. It has been a few days since his arrival, and still, his shinsoku and techniques pale when pitted against his master. As he is knocked out from every blow, the past comes back to him, and Hiko, though tough on his student, wakes him up after every session. As Hiko's patience wears thin, he wakes up his apprentice by reminiscing of the past, such as when a young Kenshin wet the bed, to even having eaten dangerously "funny" mushrooms when he was hungry and shrewish.
Mentioning in turn of how grand, yet, twisted, antisocial, brusque, and vindictive to the near point of misanthropy Hiko is as a master, Hiko turns the conversation around, mentioning that there isn't a more forgiving master around for a "stupid apprentice" that abandoned him, and that he is growing bored of his apprentice's struggle to keep up with him. Making a make or break ultimatum that he is giving Kenshin a final chance to land even a single attack onto him to accept his pleas, Kenshin soars into the sky. Hiko, eying his apprentice, soars after him. The two collide in midair, with Kenshin intent on dropping a Ryutsuisen and his master countering with a Ryushosen, their clash winding throughout the waterfall valley.
Over his student's passed out body, Hiko and Kenshin collide heads upon the latter's surprise awakening. Though Kenshin forgot to land safely, having nearly gotten a concussion after dropping after the attack, Hiko shows him his bracer- A single graze has been made by Kenshin, having put all of his heart and soul into that one attack, an attempt better than any Kenshin has given so far and a chance that would have not seen any odds of success should he had gone attempts otherwise.
Walking back to his home, Hiko is ready to show Kenshin the final steps of correspondence of the Hiten Mitsurugi-ryū. As the session begins, Hiko sternly tells his student to stand extremely still and calm- Otherwise things could get very ugly. As he readies himself, Hiko reviews to Kenshin of the nine vital targets within kenjutsu, and that all styles attempt to land on or defend those very targets. However, Hiko immediately lunges forward, and flashes by his still standing student. Having made small nicks to Kenshin's body, he reveals an attack that uses the Shinsoku of the Hiten Mitsurugi to simultaneously land hits on all of these nine points, rendering defense and evasion entirely useless against its power and force: The Kuzuryusen.
Left in utter shock and awe, Kenshin is told to perform in succession the Kuzuryusen as well. Though flabbergasted at first, and learning now that Hiten Mitsurugi's training usually involves directly experiencing the brunt force of each technique, a rather harsh but effective method, and safe due to his master's excellent control, Kenshin follows through and clashes Kuzuryusen against his master's. At the end of the split second attack however, Kenshin flies, immediately defeated in that session. Getting back up, and again in surprise upon being defeated, even after successfully performing it, Hiko reveals to him that it is not just the technique that is important- It is also the user's bodily attributes that further give the Kuzuryusen its edge, and that Kenshin's technique ultimately pales when pitted against Hiko's.
Visibly in doubt now that he cannot succeed in mastering the "ougi" of the Hiten Mitsurugi, Hiko reveals that there is an ultimate attack that does surpass the Kuzuryusen- The Amakakeru Ryu no Hirameki. Kenshin, further surprised at the revealing of another ougi, comes to realize that his misjudgment and assumption upon his impression of his master announcing the Kuzuryusen, lead him to see that as the "ougi" of the Hiten Mitsurugi- which his master states that he didn't say a word of ougi, and laughs in his student's gullibleness.
Revealing now that the Amakakeru Ryu no Hirameki is to be an attack learned after the Kuzuryusen, and is the final test for all apprentices, to pierce through the Kuzuryusen's seemingly impenetrable onslaught, Hiko leaves the rest for Kenshin to vision and properly deduce of its true nature. Sheathing his sword for battojutsu, as its speed breaking past Shinsoku allows it to counter without error, however, Kenshin falls back. Putting himself into Mugyo stance with sword sheathed, he stands against his master, but reveals his eyes, as Hitokiri Battosai. Hiko withdraws, telling his student, with his soul like that, he cannot master the Amakakeru Ryu no Hirameki at all.
As the rain pours throughout the rest of the day, Hiko gives Kenshin another final opportunity to truly master the Hiten Mitsurugi, issuing him one night to reflect in introspection of what he is missing in his heart, or else perish in the final trial that awaits him in the morning. Sitting outside under the well, Kenshin stares into the distance. Hiko, in his house, having been 14 long years since Kenshin's departure, reflects upon the day he found him, and the times they have spent together, as guardian and student. Heavy emotions within, Hiko notes, the next day that will come, will be their last to spend together.
In Tokyo, at Gensai Oguni's establishment, Gensai-sensei, Ayame, Suzume, and Megumi, spend an evening at home. Under a clear night sky with the moon hanging over the distance, Megumi listens to Gensai's playful talk with Ayame and Suzume, teasing them of when Kenshin will come back home. Looking at the moon, Megumi eyes tearfully, and thinks of Kenshin, hoping for his safety.
At the Aoiya, Kaoru sits at the balcony. Worried for Kenshin, of his battle within his heart, and his willingness to sacrifice himself to save others, Misao comforts her, that Kenshin would never come to hurt her feelings or betray her. Outside in the front, Yahiko waits in the rain, even should the cold come by its deluge, to sight Kenshin and herald his arrival.
At the Kyoto Police Jail, Saito arrives, meeting with the head commissioner to interrogate the now incarcerated Cho. To his surprise however, in a cell, a man with the kanji Aku on his back, sits in waiting. Sanosuke as well, has now made his grand entrance into Kyoto.
As day breaks, so has the pouring rain. In the middle of the marshy field, Kenshin and Hiko confront each other. Asking Kenshin if he has found what was missing in his heart, Kenshin declines. To his disappointment, Hiko has nothing left for Kenshin other than brunt truths and intimidating speech, that Kenshin has reached his limits as a man- And that half of a man, who cannot ever hope to defeat Shishio, nor even the hitokiri within, that will threaten to consume him in agony, loneliness, and risk to have him kill for the rest of his days, cannot hope to learn the Amakakeru Ryu no Hirameki. As his master, Hiko has now only one duty- To lay Kenshin in rest by death, and out of his misery as a scarred and broken man.
As Hiko slowly walks forward, Kenshin, within, can only now stare in the eyes of death, menacingly making his way to him. Questioning himself now, afraid of death, afraid now of his master, who will end his life, Kenshin forces himself back into a hitokiri, to not fear the threat of death that comes after him. Hiko, visibly fierce and angry at his apprentice's ignorance, snaps forward, and readies himself to deliver the Kuzuryusen. Yelling to brace his master's onslaught, Kenshin's life flashes before his eyes. But, as Kenshin's heart is filled with sacrifice and darkness of weakness and worthlessness, a single light flashes brightly, echoing of compassion and love from a long time ago- And Kenshin must stay alive.
Before Hiko's blade even touches him, Kenshin grips his sword, and pulls it forward, flashing faster than Shinsoku. As Hiko immediately makes it past him, Kenshin has now survived, and passed the last trial of Hiten Mitsurugi. Standing as if unfazed, Hiko weakly states now, that the hitokiri within, as it stands for his fatalism, even for his own life, is not the power within he is looking for, as self sacrifice, even for selfless purposes, is just a tiny ripple in the ocean of life. To live on no matter what odds, the wellspring of the Amakakeru Ryu no Hirameki's strength, is the true power of all of Hiten Mitsurugi, and is now at Kenshin's command. As Hiko is on his last legs, he smiles, and reassures Kenshin, he has nothing to worry about- His death is the fate of all of those of the Hiten Mitsurugi, and that he should not look at this as another life taken under his vow to never kill again.
Short of breath, Hiko immediately succumbs to his pain, and lands into the large mire, unconscious. Kenshin, now realizing just what he has done, having fatally slain his adoptive master, screams in agony of his actions, and rushes to aid him by his side.