While researching the Amanto War, a reporter interviews Nagai, a former reporter from the war in order to know about the White Demon's (Gintoki's former Joui ego) activities in such time. He chronicles the events from war, explaining how the samurais decided to fight against the aliens. As Nagai is about to talk about the White Demon, he replaces him with the fictional robot Gundam to celebrate the 30th anniversary of the franchise with the same name.
A journalist wants to find information on the war between the Joui and the Bakufu. To do this he travels to a rural village and questions an old man called Nagai who was a reporter during the war. The Amanto came and used their superior technology to force the Bakufu to force them to submit, the war then began. The Nagai mentions Katsura, Takasugi, and Sakamoto but not Gintoki.
The journalist wants to know about the White Devil so Nagai then tells a story of when Katsura and Takasugi were stuck in the trenches under fire. The Amanto ships are shot down and a Gundam stands in the dust.
Turns out it was something for the thirtieth Gundam anniversary, the reporter and Nagai looking a lot like Kai and General Revin probably gave it away.
- Katsura Kotarou (Flashback)
- Takasugi Shinsuke (Flashback)
- Sakamoto Tatsuma (Flashback)
- White Shiroyasha (flashback)
Kagura starts going to Kabuki-cho's physical fitness lessons where she meets a kid named Hongou Hisashi, whom she befriends. Suffering from a dangerous disease that weakens his body, Hisashi is absent from various lessons even though he promised Kagura to go to every lesson. During a rainy day, Kagura is the only person to come to the lesson, but Gintoki and her friends decide to join her. Next day, Hisashi returns to another lesson and sees Kagura once again.
Kagura wakes up with the radio as an alarm and bursts out. She arrives in the park where there are people preparing to do exercises the only kids in the class are her and a boy, Hisashi. The next morning she wakes up the same way and does the exercises.
This continues day after day until only her and Hiashi are left, after the exercises end Hiashi offers to stamp her card. They talk on a park bench where Hisashi is determined to do the exercises despite having ill-health and at the end they both promise to do their best.
Day after day they do their exercises each day with a different instructor, over the course of this they become friends.
After missing a day due to rain Kagura arrives at the park to find Hisashi not there.
She finds out that he had been hospitalised for doing the exercises in the rain she tells him that until he comes back it will always be raining. She takes his card to complete and continues to exercise doing ‘s share of exercise as well.
One day it rains again and the radio breaks, Gintoki arrives as the instructor with everyone else also exercising. They continue and more and more people join in. At the end when people are getting their cards stamped, Kagura is looking at her stamps and a hand pats her shoulder, she turns around and smiles. The rain stops.
- Kagura (Main Character)
- Hongou Hisashi
- Sakata Gintoki
- Shimura Tae
- Katsura Kotarou
- Sarutobi Ayame
- Hasegawa Taizou
- Shimura Shinpachi
- Part A is a tribute to Gundam's 30th Anniversary, which was in 2009.
- The reporter in Part A is a parody / copy of the character Kai Shiden from Mobile Suit Gundam, who becomes an investigative journalist in Zeta Gundam and an information broker in Gundam Unicorn.
- The old man Nagai is based on the character General Revill, who was th commander in chief of the Earth Federation forces in Mobile Suit Gundam.
- Also the story ends with the RX-78-2 gundam saving the characters in the flashback.