Tae decides to re-open the family dojo and thankfully a former student returns to help. But there may be more to him then meets the eye.
Tae sits in front of her father's gravestone, giving offerings, and tells her father that it is now time to restart the dojo. She admits that she had to save up the money to start it and prays for success. She is interrupted by the arrival of someone who recognizes her. Later, she tells Shinpachi of those plans but Shinpachi remarks that she had forgotten it until re-watching this anime. Gintoki, who along with Kagura was with the siblings, remarks that people no longer care about learning swordsmanship but Tae believes that they still need to keep the old traditions alive despite this modern age. She adds that they also need to adapt to the times, as such their dojo style, Tendou Mushin, should focus on using beam sabers!! Shinpachi demands who will be the instructor for beam saber use and the figure whom she encountered arrives. A stunned Shinpachi tearfully hugs him, happy that he was alive all this time.
The figure, Obi Hajime, was a former student from the Shimura dojo while it was still open. His skills were such that he became one of the school's instructors at a young age and gained notoriety throughout Edo. He was chosen to study abroad in space, but he disappeared when the terminal suffered an accident. Obi reveals that the teleporting accident transported him to a planet where he learned the beam sword fighting style from the natives, resulting in him not only mastering it but gaining the title of "Galaxy Sword Master" as he fought through planet after planet. When no one able to challenge him, he decided to return to Edo to see everyone. Saddened that the Tendou Mushin school had shut down, he tells the siblings that he will help the school become great again.
The enthusiastic siblings and Obi, along with the apathetic Gintoki and Kagura, stand on a bridge to promote the school. With no one stopping, Obi suggests to Gintoki that they should spar, despite Gintoki's lack of knowledge of beam swords, believing that Gintoki will inherit the dojo due to Tae and him dating. Shinpachi refutes this stating that Obi was Tae's first love. Both males earn the elder Shimura's wrath as she shoves the beam sabers up their behinds. Unfortunately, they are confronted by Kondou and Kyuubei, who overheard Shinpachi's proclamation and decide to team up and attack Obi in the guise of wanting to join. The two shoot cannons at Obi, who appears unscathed and he retaliates by forming a laser beam from his right arm, revealing it to be robotic. In space, a ship carrying short, green-skinned Amanto, hovers around Earth. They try to contact their agent, Kenofi, without success. Annoyed with his freelance nature, they decide to let him be.
Later that night, the Shimura siblings and Obi celebrate the re-establishment of the school with their other members, the scared Kyuubei and Kondou, Kagura and the still apathetic Gintoki. Kondou asks Obi about his robotic arm and Obi show them all that most of the right side of his body was a machine, shocking everyone (except for the apathetic and now drunk Gintoki) The cyborg reveals that the teleportation accident that transported him to another planet also destroyed most of the right side of his body, actually killing him. The natives were advanced enough to revive him with robotic parts and it was thanks to this that he was able to become one of the strongest swordsman in the galaxy. Before he continues, Obi abruptly shuts down and collapses. Believing it was because he didn't get his true food, gasoline mixed with shouchu, Tae rushes to get it while Shinpachi and the others take him to a room.
A while later, Gengai checks on him and gives Tae and Shinpachi his diagnosis... Tae's poisonous cooking. Thankfully the "dark matter" was purged from him and he is now resting. He also tells the siblings that Obi's robotic half was the only thing keeping him alive before leaving. Shinpachi laments his brother figure's state, but Tae remind him of their promise to Obi, to smile even in the face of sadness. They should be happy that they were able to see him again. Kyuubei, Kondou, Gintoki and Kagura overhear the siblings' conversation and the first two quietly leave.
The next morning, Hijikata, Okita, and Toujou ask about their respective bosses' whereabouts just to see them both suicidally depressed. At the same time, Gengai calls out to Gintoki to talk about something else he found within Obi's body. Hijikata tells Kondou about the planet Beam, famous for creating beam cannons, and how they are threatening Earth due to Earth deciding to pass a law that makes the manufacturing and selling of beam cannons illegal. As Kyuubei watches the Beam Amanto's broadcast, telling the planet that they sent something to them, Gengai reveals to Gintoki that Obi has a timed powerful beam cannon that is set to fire at the planets of the Alliance. If it is fired, then Earth will be in danger of being wiped out in retaliation.
- Shimura Tae
- Shimura Shinpachi
- Sakata Gintoki
- Obi Hajime (debut)
- Kondou Isao
- Yagyuu Kyuubei
- Hiraga Gengai
- Hijikata Toushirou
- Okita Sougo (cameo)
- Toujou Ayumu (cameo)