Gekiganger 3

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 OVA is a compilation of the scenes from Nadesico, a new "movie", and is a parody of many mecha series from the 80s. (Source: ANN)