This was the 14-minute movie that was screened in theaters with Keroro Gunsou Movie 3. It became the prequel to the Mushakero in season 5 of the main Keroro Gunsou anime series. It takes place in Ranstar where the Keroro platoon are up against the Vipers. The whole setting of Ranstar is based on the Sengoku Era of Japan, and all characters are dressed in that fashion.

Mini-OVA specials bundled with each Blu-ray/DVD volume of Kenzen Robo Daimidaler.

Battles continue between Penguin Empire, the mysterious life form which arrived on earth all of a sudden, and Beauty Salon Prince, the secret anti-Penguin organization. In order to fight Penguin Empire's gigantic Penguin Robot, Beauty Salon Prince has developed their ultimate weapon, Daimidaler, and is now looking for the pilot. They choose Koichi Madanbashi, a hot-blooded high school boy who is mad about big boobs, because he is the factor of Hi-ERo particles, the source of unknown energy. (Source: Showgate)

A is the retelling of the original anime's finale.