Chapter 939 is titled "The Old Leopard Never Forgets the Way".
Hiyori tells Zoro how she escaped from Oden Castle's destruction 20 years ago with the help of the retainer Kawamatsu. In the Flower Capital, the people with the Kozuki Family's mark on their ankle are all corralled in a prison in the Rasetsu District for everyone to see.
In the Prisoner Mine, Luffy and Hyogoro fight Alpacaman and Madilloman. Luffy tries unsuccessfully to unleash a ranged Busoshoku Haki attack, but after realizing what Haki is, Hyo performs the exact desired attack and offers to help Luffy in learning it.
Zoro is shocked to find out that Hiyori is Momonosuke's younger sister, and his exclamation confirms to her that he is still alive. Hiyori is happy to know this, saying that Zoro's arrival during the Kozuki Family's rumored return must mean that he is Momonosuke's ally. She does consider that Zoro might be an enemy trying to capture her brother, but Zoro assures her that he is an ally. Hiyori then explains how Momonosuke was sent 20 years forward in time, and Zoro is suspicious about Toko's presence, but Hiyori assures him that she is a rare friend who has known the truth about her and helped her push forward. Hiyori remembers the death of her parents and disappearance of her brother 20 years ago, where she did not believe Momonosuke's promise to return in 20 years and lost her will to live. Zoro asks why she did not go with him, and Hiyori reveals that it was to ensure the Kozuki Family's bloodline would survive if the plan did not go right.
She was taken care of by the retainer Kawamatsu, who managed to secretly take her out of the burning castle by digging down into the water channel and swimming through it. Kawamatsu had done everything he could to cheer her up, eventually breaking her out of her silence. They were separated when she was 13, but Hiyori is confident that he is waiting somewhere for the final battle. Zoro then tells her that Inuarashi and Nekomamushi are here, which overjoys her as she thought they had died. Zoro notes the Nine Red Scabbards he has met and wonders who the remaining three are. Hiyori reveals that they are Kawamatsu, Denjiro, and Ashura Doji, and she does not know where any of them are, but is confident they will understand the secret message to the final battle. Zoro reveals that the shogunate found out about their rendezvous location and are arresting their allies, which worries him, but he decides to just rest for the time being. Hiyori gets excited about seeing her brother and retainers, but considers not doing so until after the final battle.
In the Flower Capital's Rasetsu District, Orochi's forces throw the Kozuki Family's allies into a prison. Fukurokuju mocks how they were exposed, and the prisoners try claiming that the crescent moon symbol on their bodies means nothing, but Fukurokuju replies that the accompanying messages in their possession leave no doubt. The citizens are able to see inside the prison and marvel at how many people were secretly loyal to the opposition, and Orochi's forces use the prisoners as an example of what happens when you oppose Orochi and Kaidou.
In the Prisoner Mines, Kawamatsu remarks from his cell that he wants to sumo wrestle as Alpacaman and Madilloman enter the Sumo Inferno ring. Madilloman proclaims that he will quickly put an end to Luffy and Hyogoro with his Seastone bullets, not caring about the audience's pleas against such a quick ending. However, Luffy tells Hyogoro to run to the right, bend his knees, and jump. Hyogoro does this, and in the process dodges Madilloman's bullets, dodges Alpacaman's spit, and headbutts Alpacaman on the chin. Hyogoro is stunned to see that Luffy can predict the future, and Luffy dodges Madilloman's shots with ease, frustrating the Gifter. Luffy then moves to attack Madilloman, and Madilloman uses his armadillo SMILE to shield his head, but to his surprise Luffy does not hit him as he continues unsuccessfully attempting to project Busoshoku Haki from his palm. Luffy then saves Hyo from Alpacaman, and Hyo wonders what Luffy is trying to do. Luffy explains the move he is trying to acquire, with the hope of using it to break through Kaidou's scales. As they dodge their opponents' attacks, Hyogoro realizes that Busoshoku Haki is the outsiders' term for an ability used by samurai to strengthen their swords, revealing that he learned this technique long ago. He then races toward Alpacaman and hits him with a powerful shockwave, defeating him. Luffy affirms that this is the exact technique he wants to learn, and asks Hyogoro to teach it to him.
- The reason Hiyori was not sent to the future was to ensure the Kozuki Family's bloodline would survive just in case the plan to take down Orochi did not go right.
- It is revealed that Kawamatsu helped Hiyori escape Oden Castle 20 years ago.
- All members of the Nine Red Scabbards are confirmed.
- The Heart Pirates are shown incarcerated in the Rasetsu District prison along with other rebels.
- According to Hyogoro, Haki is a concept used by foreigners outside Wano Country while within the country, Haki is referred simply as the will of a samurai.
- Hyogoro can use Busoshoku Haki and he demonstrates the advanced technique Luffy is trying to learn.
- The chapter's title is a pun based off the Chinese and Japanese proverb "An old horse knows the way" (老いたる馬は道を忘れず Oitaru Uma wa Michi o Wasurezu?). Horse is replaced with Leopard, the Japanese word for which is Hyō, referring to Hyogoro.