In Odaiba, Tokyo, Mirai Onosawa and her younger brother Yuki are attending a robot exhibition when a powerful earthquake shatters the city.

Amidst the rubble of a collapsing building on Mari Kusanabe Street, Mirai frantically searches for Yuki, aided by a female motorcycle courier named Mari who had offered her assistance.

Mirai, Yuki, and Mari resolved to make their way home together, but their journey quickly revealed a depth of peril within the crumbling city they had not anticipated.

Leaving Odaiba behind, the trio sought a suitable location to gather provisions and prepare for the arduous journey ahead. However, after a brief discussion, Mirai and Yuki wandered away from Mari, and soon found themselves in serious peril…

Seeking refuge within the walls of her school, Mirai and her companions find little peace during the night. The tremors of aftershocks disturb their rest, and a pervasive sadness settles upon them as they witness the grief of those who have…

They arrived at Mari’s place of work, but she collapsed, overcome by a sudden wave of weakness. As this happened, the children were startled by Aya, a colleague of Mari's, who burst into the building with a baseball bat, the sound of her en…

Rescue robots appeared, a captivating sight for Yūki, and they guided him to a new acquaintance. This friend shared Yūki’s passion, and was the same age as Mirai. Yet, the journey thus far seemed to have worn Yūki down.

Yūki fell abruptly, and was rushed to the hospital, leaving Mirai consumed by worry for her brother's condition.

Mari arrived home only to discover her house had been destroyed, and the whereabouts of her mother and daughter were still unknown. Determined to help, Mirai and Yūki learned of a nearby elementary school providing shelter to those affected…

The truck ride back to their hometown was filled with quiet conversation between Mirai and Yūki, until Yūki brought up the subject of his own death. She chided him to cease such talk, explaining that she and her parents would be devastated …

Mirai accompanied Yūki home, and was welcomed by her parents. A month later, while Tokyo steadily rebuilt itself, the city bore the indelible marks of the disaster. Mari visited Mirai, returning her cell phone and Yūki’s backpack. As Mirai …