Goh, Jiro, Aki, and Ken are all on a mountain excursion. While enjoying the day, Jiro takes a photograph of Goh and his girlfriend in the top of a precipice. As they pose, Goh's super hearing picks up a shrill sound that nobody else hears. Later, Aki has the pictures developed and to her surprise, some sort of monster has photo bombed their picture without them knowing it. MAT investigates the location and comes up with nothing except scratch marks on some rocks by the river. They think that little Jiro has somehow doctored the photo as a prank. When the monster does reveal itself, MAT members discover it's a rock-like chameleon beast, assimilating with its surroundings. They devise the 'Rainbow Plan', an air and ground maneuver where the Monster Attack Team will pellet the thing with a myriad amount of colors so that the monster will remain visible. Goh Transformed into Ultraman & the monster was defeated.
坂田兄弟と郷はハイキングに行き、束の間の楽しい時間を満喫していた。そこで次郎が記念に撮った写真には、怪獣の姿が写っていた。その正体は、自分の体色を周囲の色に合わせ姿を消す能力を持つ怪獣ゴルバゴスだった。MATはゴルバゴスの姿を見失わないように、七色の塗料を吹きつける「レインボー作戦」を敢行する。