Gekiganger 3: The Movie

ゲキ・ガンガー３　熱血大決戦

Ken, Joe, and Akira, three high school students, must combine their three mecha into Gekiganger III to defeat the evil Prince Akara and Emperor Hyperion. The OAV is a compilation of the scenes from Nadesico, a new "movie", and is a parody of many mecha series from the 80s.

(Source: Anime News Network)