Mirai Onosawa and her younger brother Yuki are visiting a robot exposition at Odaiba, Tokyo, when a massive earthquake strikes the city.

Mirai looks desperately for Yuki after the earthquake inside a colapsing building along Mari Kusanabe, a female motociclist courier who offered herself to help her.

Mirai, Yuki and Mari decide to reach their homes together, but just after starting their journey, they find that there are far more dangers in the colapsing city than they imagined.

Having finally left Odaiba, the trio find a place to gather supplies and prepare theirselves for their long walk, but after having a discussion, Mirai and Yuki stray from Mari and end up in serious tr…

Mirai and company take shelter at her school's premises during the night, but their stay becomes far from peaceful as they are constantly plagued by aftershocks and depressed by the sight of those who…

The group reaches Mari's workplace, where she loses conciousness because of amenia. During that time the kids are suddenly frightened by Aya, a colleague of Mari, who noisily enters the building carry…

Rescue robots fill the scene, fascinating Yūki and leading him to meet a new friend, who shares his interest and is the same age as Mirai. However the journey so far seems to have taken its toll on Yū…

Yūki collapses suddenly and is taken to the hospital, where Mirai agonizes over her brother's fate.

Mari finally reaches her home, only to find out that her house was destroyed and the fate of her mother and daughter remains unknown. Mirai and Yūki decides to help and discover that there is a near b…

Mirai and Yūki are talking in the truck on the way back to their hometown, when Yuuki brings up the subject about his death. She tells him to stop talking about this nonsense, and that she and her par…

Mirai "escorts" Yūki back home, and is reunited with her mother and father. One month later, Tokyo is well into recovery and reconstruction, but it is still clear that the city has been permanently ch…