Just like the two previous Cybernetic Hi-School games, the third part is a strip quiz game. This time, it is centred upon Gainax's famous Gunbuster animation videos.
You, as an alpha-class Top, are supposed to win three keys to pilot the Great Gunbuster robot against the cosmic threat to humanity. The keys are held by Jung-Freud, Kazumi (oneesama) and Noriko, and you must retrieve the keys by defeating each character in a quiz game, which has the side-effect of stripping them of all their clothes.
Each character asks questions around a certain theme; Jung-Freud asks about the Soviet Union and military technology, Kazumi asks about fashion and Noriko asks about cult science fiction and animation.