Two years have passed since the final battle with Sephiroth. Though Midgar, city of mako, city of prosperity, has been reduced to ruins, its people slowly but steadily walk the road to reconstruction. However, a mysterious illness called Geostigma torments them. With no cure in sight, it brings death to the afflicted, one after another, robbing the people of their fledgling hope.

Once again, Musashi has encounter Ultraman Cosmos. Now Ultraman Cosmos has gained some new modes to defeat Scropis. Musashi has joined Team Sea to save the Blue Area. But there is mysterious evil monster, Sandros, who wants to destroy the Earth. Now it is up Musashi and Ultraman Cosmos to defeat Sandros and who’s the other Ultraman?

When he returns to Earth to attend the wedding of his friend in Saipan, Musashi meets a beautiful girl named Shau who claims to come from the bottom of the sea. Just then, Monster Scorpis reappears in the sky above the island and Musashi faces the monster in order to protect the girl. What is the girl's true form? And what is the strange shadowy form that follows the monster Scorpis?

The period of late World War II, Toshiko was living in downtown Tokyo with her family. Japan was more towards losing the War at the time and people were suffering with lack of materials. On March 10th 1945, she lost her mother and two younger sisters by the bombing in Tokyo. She picked up "Glass Rabbit", which shape was changed by the fire, out of the wreck one day and she experienced the terror of the War. Moreover when she had to evacuate to the suburbs, her father was killed by US army on the way at the station. Now that she became all alone, she felt so lonely and despaired that she almost found no meaning to be alive. But despite of her loneliness and sorrow, she aroused herself, thinking about all her family who were gone. "I must survive for my family.... Otherwise, who will be visiting their grave." This is the story of one girl, which should not be forgotten.