A large monster attacks Japan, but dies suddenly. While the people rejoice and bask in relief, the giant corpse left behind begins to slowly rot and bloat. If it explodes, the nation will be destroyed.
Two historical incidents that deepened the friendship between Japan and Turkey are connected in this story of friendship and compassion: In the night of 16 September 1890 the Turkish frigate Ertuğrul is caught up in a typhoon and sinks off the Japanese coast. Risking their own lives, local villagers are able to rescue 69 Turkish sailors. Although being very poor and having hardly to eat, the villagers share what little they have with strangers from a country 9,000 kilometers away. 95 years later, during the Iran-Iraq War, more than 300 Japanese are stranded in Tehran. In the morning of 19 March 1985 a Turkish Airlines aircraft takes off for Tehran to evacuate the Japanese. But the remaining Turks at Tehran Mehrabad Airport still need to be convinced that they won't be able to board their own country's rescue flight.
The Underground Empire Badan makes its move, intending to invert the world. Kouta and Mai are pulled through one of these inversions where the discover a boy named Shu, who also holds the power to invert the world. As the Riders fight to protect Shu, Fifteen appears again, seeking Shu. As Kouta flees, past Riders gather and fight one another, split between the Showa and Heisei era Riders. But, the truth of Badan is not as it seems…
The Kamen Rider Club discovers that the Dai-Zangyack fleet is moving towards Earth, led by Captain Marvelous as their Great Emperor. With many revived Super Sentai villains under his command, Captain Marvelous plans to obtain the Great Power of the Kamen Riders which is said to be "Ultimate Treasure in the Universe". Meanwhile, Tsukasa Kadoya becomes the Great Leader of Dai-Shocker once again and recruits past enemies of the Kamen Riders to take down the Super Sentai teams.
A scientific exploration in search of a new energy source unleashes a group of powerful demons who begin possessing human bodies and destroying civilization. Close friends Akira and Ryo wind up on different sides of this epic struggle. Akira’s inner strength allows him to maintain his identity and fight for good, but the weaker Ryo is completely overtaken by Satan himself.
A special retrospective of the two franchises, with segments making comparisons between the different characters, their weapons, powers and so forth. The final segment of the special is the short film "Super Battle: Ultraman vs Kamen Rider" The main characters, Ultraman and Kamen Rider 1 appear on the scene separately, each fighting an original kaijin and kaiju. When the two monsters are nearly defeated, they merge into a more powerful kaiju. Ultraman experiences trouble and calls for Kamen Rider 1's help. Kamen Rider 1 is then able to grow to enormous size to fight alongside Ultraman.
