Keroro Gunsou: Mushakero Ohirome Sengoku Ranstar Dai Battle

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...