According to Aniplex, a 10min short anime of Gintama "Shiroyasha Koutan" will be released on September 30th. It was shown at Jump Super Anime Tour 2008 and had never been released as a DVD. It's a trailer of an imaginary Gintama movie. Gintama OVA shown at Jump Anime Tour '05 is also included in the DVD.

China’s Warring States period, a raging dragon that would raze the land for 500 years, saw many kingdoms rise and fall, making way for the next generation of kings and generals to fight for supremacy. Eventually, seven powerful states emerged from the endless cycle of warfare. In the kingdom of Qin, Li Xin, a war-orphaned slave, trains vigorously with fellow slave and best friend, Piao, who shares his proud dream of one day becoming a Great General of the Heavens. However, the two are suddenly forced to part ways when Piao is recruited to work in the royal palace by a retainer of the King. After a fierce coup d'état unfolds, Piao returns to Xin, half dead, with a mission that will lead him to a meeting with China's young King, Ying Zheng, who bears a striking resemblance to Piao. Kingdom follows Xin as he takes his first steps into the great blood-soaked pages of China's history. He must carve his own path to glory on his long quest to become a Great General of the historic Seven Warring States. [Written by MAL Rewrite]

Kenshi Masaki has been kidnapped and brought to the world of Geminar by a mysterious group. To get back home, he agrees to help them assassinate the newly crowned empress of the Shtrayu Empire, Lashara Aasu XXVIII, using a giant robot called a Sacred Mechanoid. As her army fights them off, Lashara takes note of Kenshi's abilities and demands that her attacker be captured alive, only to find out that the pilot is male which is extremely rare on Geminar. Believing it to be a waste to kill him, she makes Kenshi her attendant. As the empress' new servant, Kenshi is required to accompany Lashara to the Holy Land, an academy where Sacred Mechanoid pilots hone their skills. His arrival attracts attention, but Kenshi is unaware that something sinister is brewing within the academy and it could plunge the entire world into war. [Written by MAL Rewrite]

Unsuspecting inhabitants of the planet Earth are going about their business, enjoying a bright and particularly beautiful sunny day, when a young Japanese boy spots a shiny object falling from the sky... Has an alien invasion finally begun? Elsewhere in Japan, Keroro, frog sergeant and leader of the Space Invasion Army Special Tactics Platoon of the 58th Planet in the Gamma Planetary System, has discovered the perfect hideout. He infiltrates the home of the Hinata family in an attempt to establish a headquarters that he and his troops could use to prepare for world domination... but earthlings Fuyuki and Natsumi Hinata are too much for him to handle! Natsumi instinctively calls them out of hiding, leaving the hapless sergeant no option but to reveal his secret identity. The two siblings soon welcome the sergeant to their home, all thanks to Fuyuki’s generos—err... curiosity. The Sergeant has successfully infiltrated his first target area! Or has he? Join Keroro Gunsou in his dastardly attempt to take over the world!