Chapter 19 is titled "Whatever It Takes!!!".
On a satellite orbiting Planet Kenka - the site of the infamous battle royale - a mysterious duo makes preparations to participate. As Hachimaru and company make their way to Kenka, Daruma decides to have Hachimaru train by dueling with Ryu. Because of the massive difference in skill, Hachimaru has to push his body and mind to their limits to have any hope of holding his own in the duel.
Inside a structure carved into a satellite orbiting the planet where the battle-royale is being held, two beings - a mysterious man and a large being with horns - enter a room full of Samurai Keys. Noting the upcoming event, the small man tries to pick a Key to take into the fight with him. Meanwhile, Daruma's Holder continues its flight to the planet. Inside, Kotsuga is pleading to have his manacles removed, arguing that he should be given some freedom since he gave them the coordinates to Planet Kenka. Daruma decides to comply, but warns him to behave since he is still trapped inside his Key Holder. Kotsuga notices that he leaves Ryu's restraints on, and Daruma explains that he only took his cuffs off because he is a weak bushi, unlike his samurai partner.
After removing the cuffs, Daruma studies the data his body gathered from the fight with Ryu. Visualizing Ryu fusing his Samurai Souls together gives him and idea of who his prisoner is. He asks Ryu directly, but he does not understand the question. Daruma believes he is joking, but Kotsuga explains that Ryu is an amnesiac he took in after finding wandering a planet aimlessly. Though it seems like Ryu is yanking his chain, he really only takes everything literally. Hachimaru then comes into the room requesting more training, and Kotsuga insults him, saying he is far weaker than Ryu. Halfway through his rebuttal, Ann cuts him off to offer her own comeback, though she elbows Hachimaru in the face while doing so. Kotsuga then cuts her off when he recognizes her as a Princess. He tells her that made a lousy choice for a Samurai and flirts with her, only to be met with a cold shoulder. While that happens, Daruma removes Ryu's cuffs, deciding to give Hachimaru practical training through a duel, and warns that it will be painful. Nonetheless, Hachimaru is determined to go through with it, thinking about his need to surpass Ata.
Daruma then lays out ground rules for a duel between Hachimaru and Ryu: they will battle for points awarded for any body contact with a blade, and whoever has the most points wins. With the turtle Holder's AI serving as judge, they extend courtesies and begin. Hachimaru calls for a clean fight, which Ryu takes to mean he can fight like he normally does. Ann and Hayataro both offer to lend their support, but since Ryu doesn't have a Holder or a Princess to pray for him, he asks them to stay out of the fight in the spirit of fairness. They reluctantly agree, and Kotsuga becomes intrigued by his fairness. The first round begins, and while Hachimaru tries to think of a move, Ryu stabs in the head and scores a point before he finishes his thought. Unimpressed by the display, Kotsuga continues flirting with Ann. Acknowledging his opponent's speed, Hachimaru has to tell Ryu to remove his blade from his head. In the second round, Ryu easily wins again by cutting Hachimaru's forearm off. While Ann becomes worried, Kotsuga gets bored watching Hachimaru reattach his arm. However, Ryu notices that he reattached his arm unusually quickly.
As the duel continues, Hachimaru racks up repeated losses, but persists no matter how many time he is stabbed and cut. After losing for the 31st time, Kotsuga mocks him for falling for the same tricks repeatedly. Ann wants Daruma to give some advice, but he states that solving the problem himself is part of the training. Ryu notices that Hachimaru is beginning to understand his fighting style, so he decides to switch things up by pulling his second Samurai Soul out. Catching the change, Hachimaru notes that he will have start studying Ryu's movements from scratch. As he waits for his latest cut to heal, he gets a nostalgic feeling, being reminded of playing online battles against Nanashi. When the next round begins, he anticipates that Ryu will extend his blade to strike at a distance. Though proven right, he loses for the 32nd time, having underestimated how far Ryu can extend his blade. While he tries to strategize, Kotsuga tries to flirt with Ann again, prompting her to cheer for her samurai. Hachimaru considers tossing his Soul Katana to overcome Ryu's reach, but he knows his blade might not reach Ryu before he is struck.
As round 33 starts, Hachimaru decides on a plan. He goes for a heavy swing, which Ryu can tell will not reach him. Hachimaru then shocks everyone when he unsheathes his regular katana to slice his sword hand off mid-swing, sending it flying toward Ryu. Kotsuga is most shocked that he would make such a bold move to extend his reach, but he also catches that Ryu's blade is extending fast enough that the round will end in a draw. However, Hachimaru goes even further to ensure he wins, using his katana to take his head off. His drastic move prevents Ryu's extended blade from touching him, while his blade cuts Ryu's cheek, flies past him, and lands in the couch Kotsuga was sitting on mere inches from his head. As his head hits the ground, the Holder AI grants Hachimaru a point. He celebrates his small victory and bemoans the pain he's in, thinking to himself that he must do whatever it takes to grow stronger.