One day, college student Keiko, who is looking for a job, learns that the person she had feelings for has committed suicide. Keiko wonders if she was the cause of this. Classmate Mami, through her boyfriend Takuya, tries to introduce Keiko to Kazuo, a member of Takuya's theater company. However, Keiko, who met Takuya, has a special feeling for him. Miyata, a young man who seems to be hiding in the darkness of everyday life, meets Keiko one day.
The time of the New Generation Heroes is drawing to a close. Hiroyuki is being targeted by a dark power, forcing the other Ultra Heroes, from Ginga to R/B to appear and help the Tri-Squad battle these evil forces. But among them is Taiga's father? What has happened to Ultraman Taro?!
Somewhere on a distant planet, X and Geed were defeated by a pair of black Ultramen who bore their likenesses in appearance. At the same time, an old enemy of Taro named Ultra Dark-Killer targeted both Zero and Grigio, forcing Taro to recruit the New Generation Heroes to stop the League of Darkness.