To celebrate the 20th anniversary of the Sgt. Frog (known as Keroro Gunsou in Japan) anime, Bandai Namco Pictures announced the launch of a new animation project and released a special trailer alongside the news release. Despite the announcement being on April Fools' Day, the official Sgt. Frog Twitter account confirmed the news using the hashtag "For real" (#本当). 

(Source: Crunchyroll News, edited)
 
Note: Title and Relations are provisional and will be updated when more info is announced.