Chapter 1 is titled "The First Key".
Daruma, the first disciple of Yasha and second-generation head of the Kongo-Yasha Style, is a samurai on the mission to find the seven keys to open Pandora's Box in order to save the galaxy. He meets a feeble and disabled boy named Hachimaru who wishes to be a samurai but has to remain tethered to a huge life support machine at all times.
Hachimaru's father, trying to create a mobile life support system for his son, needs a vital part for it known as a Locker Ball. While he is away purchasing a locker ball worth 200 million yen from a ronin, the ronin notices that Hachimaru's father possesses the key that seals the Samurai Soul of Dojikiri Takatsuna, a legendary katana known as Bloodsucker. It turns out, Hachimaru's heart is powered by the energy of the katana.
The ronin attempts a failed attack on the legendary canine samurai Daruma. The ronin takes Hachimaru's father as a hostage and forces Daruma to retreat, attacking him with a remote star weapon. In order to take the katana, the ronin forces Hachimaru to commit seppuku using the seppuku blade from the locker ball by threatening him with his father's life. Hachimaru commits seppuku and the vampire blade is now in the ronin's possession.
Meanwhile, by committing seppuku, Hachimaru receives the blessings of the god of war, gaining the three chakra bodies and becomes a samurai. With this new strong samurai body and the technique he learned in Daruma's video game, Hachimaru defeats the ronin and protects his father.
Daruma hints at a new journey ahead to find the remaining six keys together with the "true key" known as Hachimaru.
The samurai have a duty to protect the galaxy. Somewhere in the galaxy, a samurai known as Daruma is entrusted with a mission by Yasha to seek out Pandora's Box and the seven keys which will open it. The Pandora's box contains the means to save the stars of the galaxy and was once used by the God of War, Fudo Myo-o. Daruma is introduced as the first disciple of the great Yasha and the second generation head of the Kongo-Yasha Style.
During a clash between an unknown samurai and Daruma, who is also famously known as the Wandering Lone Wolf who travels with his Komainu holder, the unknown samurai praises Daruma for destroying his Komusubi-rank holder with such ease. Both the samurai summon their armor from their holders and prepare to attack with their true weapons. The head-on battle between the two samurai settles as Daruma uses a reckless attack to defeat the unknown samurai, who turns out to be one of the seven keys needed to open Pandora's Box.
Elsewhere, Hachimaru almost breaks his arm while playing a VR game. He is a feeble and sickly boy who has spent his life tethered to a huge life support system, and would not survive even three minutes, if disconnected from it. He has to feed on a liquid diet and has to get a regular IV therapy. Because of this, Hachimaru has never been outside of his home and spends his time playing video games on Galaxynet. He has an AI pet holder dog (which was originally a cat) named Hayataro. Hachimaru's father has always taken care of him and built him an arm with telescopic cane installed inside it to assist in walking. Now he is working on a mobile life support system for Hachimaru, so he can go outside his house, and just needs one single remaining part before it's completion.
To get that part known as a Locker Ball, Hachimaru's father deals with a ronin, a former samurai. He takes 200 million yen to ronin to purchase the Locker Ball. During their meeting, the ronin notices that Hachimaru's father possesses the key that seals the Samurai Soul of Dojikiri Takatsuna, a legendary katana known as Bloodsucker. A Samurai Soul is the true weapon of a samurai and the Locker Balls are small stars created and left behind by Fudo Myo-o. A seppuku blade is contained within it, and if someone worthy commits seppuku with that blade, they receive the blessing of Fudo Myo-o and gain a saumrai body. The samurai body is made from the locker ball with a spine-like key serving as a base and memory unit. The ronin accesses Hachimaru's father's memories with his cybernetic samurai arms to look for the Bloodsucker katana, which according to him is worth more than 2 billion yen. It turns out that Hachimaru's heart is being powered by the energy of the katana. Therefore, Ronin sets out to find Hachimaru.
Hayataro by mistake fetched a big daruma doll for Hachimaru instead of the ball he threw. But since daruma dolls are a lucky charm, Hachimaru draws an eyeball on it and wishes for his father's safety, as well as for himself to be strong. It turns out that the daruma doll is actually the samurai Daruma himself, currently blind and trapped in a cyborg cat body. During the conversation, Daruma shows his interest in Hachimaru but also declares that it is impossible for Hachimaru to become a samurai with such weak physique. Suddenly, the ronin attacks Daruma but Daruma's counter attack Tsumujikaze: Pack Whirlwind is far superior. Daruma reveals to Hachimaru that the fight between him and the unknown samurai was in fact fictional and was part of a game he uploaded on Galaxynet to inspire youngsters to become samurai and then seek them out. Hachimaru is the eighth who Daruma has met in person who has played the game. Realizing the situation he is in, the ronin threatens both Daruma and Hachimaru with Hachimaru's father's life and cowardly attacks Daruma with a projectile weapon installed in his holder.
To remove the samurai soul Dojikiri Takatsuna, Hachimaru's heart needs to be stopped. Therefore, the ronin forces Hachimaru to commit seppuku, ensuring that his father's life would be spared. Hachimaru without a second thought does so. Now the legendary katana is in the ronin's hand, but by committing seppuku, Hachimaru receives the blessing of the warrior god Fudo Myo-o and gains Sanrinshin, the threefold body of a samurai. He then revives Hayataro as a holder. The battle between Hachimaru and the ronin initiates. Daruma destroys the ronin's samurai armor in order to Hachimaru to successfully inflict his attacks on the opponent. Hachimaru then uses the technique he learned from Daruma's game and defeats the ronin, turning him back into a Locker Ball in the process. Finally, Hachimaru's wish came true as he successfully protected his father and became a samurai.
Daruma hints a new journey ahead to find the remaining six keys together with the first "true key" known as Hachimaru.