Sergeant Keroro: Kero 0

Kero 0 runs for 15 minutes and features a cast that includes Kumiko Watanabe, Etsuko Kozakura, Jouji Nakata, Takehito Koyasu, and Takeshi Kusao. This short film was presented in theaters alongside Keroro Gunsou Movie 4, making it a unique part of the franchise's promotional efforts.

As a prequel, Kero 0 provides context and background for fans of the series. Collectors of animated works, especially those interested in the Keroro Gunsou universe, may find this short film an important piece to add to their collection. Its connection to the theatrical release adds to its appeal, showcasing an early glimpse into beloved characters and storylines.