Tokyo Magnitude 8.0 (Original Japanese)

Mirai is in the first year of junior high school. She is a typical girl who feels somewhat unsatisfied with her current life. Even though it's summer holiday, she has no particular plans, and her parents are forced to take care of her younger brother, Yuki. But when they go out together to Odaiba, they are hit by a massive earthquake measuring 8.0 on the Richter scale!

Mirai runs into a half-destroyed building, looking for her brother Yuki who has been separated since the disaster. With the help of Mari, she continues looking for him amidst the chaos of fleeing people, but a series of secondary disasters - aftershocks, fires and liquefaction - prevent her from doing so. Can the two be reunited?

Mirai and Yuki, together with Mari, whom they met on the way, are heading towards their home. As the damage becomes clearer overnight, the three are guided by the Coast Guard to the pier in order to escape Odaiba by water bus. Despite being caught up in the panic caused by the aftershocks, the three managed to board the ship...

After receiving relief supplies, they take a breather for a short time until Mirai's irritation turns into taking it out on Yuki, and they have a big fight. However, an active fault that appeared under Tokyo Tower with the aftershocks obliterates it all!

When they stop at the secondary school Mirai attends, it is full of people who have had difficulty returning home. Many cold dead bodies are also brought in, and the transformation of the familiar school is heartbreaking for Mirai. Mirai is kindly treated by an elderly couple who work there as volunteers, and her view of adults, including Mari, changes. She seeks what she can do to help.

The group heads for Setagaya via Azabu Juban. However, during the journey, they hear news of the burning down of Sangenjay, Mari's hometown. Mari tries to seek more information, but without any way to get it, she falls ill. Mirai and Yuki then put an idea into action to help Mari return home as soon as possible.

Mirai and Yuki get to know Kento, a boy who pursues rescue robots used by the Hyper Rescue Team. At first, they make fun of him as a robot geek, but gradually they are attracted to his words and actions as he seriously considers the future. Meanwhile, he is trapped in the rubble with the rescue robot he was chasing!

Yuki suddenly loses consciousness and collapses. He is triaged and taken to hospital, but his condition is not good. An operation is performed immediately, and Mirai and Mari wait in suspense. However, when Mirai wakes up, she sees Yuki in good health. The three of them start their journey home again.

The three arrive in Sangenjaya. However, the damage caused by the fire was far beyond Mari's imagination. She desperately searches for her daughter and mother, but is misled by various speculations and rumours, and is unsure of their whereabouts and whether they are alive or dead. Then, thanks to Mirai and Yuki's quick thinking, Mari is reunited with them.

They parted ways with Mari. They are almost home when they decide to stop by Yuki's primary school. There, Mirai sees Yuki's footprints, but every time she looks at them, for some reason, she bursts into tears. Yuki should be here, but why? Unable to dispel her doubts, Mirai heads home with Yuki.

Finally arrived home. Reunited with her family after a long time. Having lost so much in the earthquake, Mirai is left with a void in her heart and time passes. When Mari comes to greet her parents, Mirai is handed the mobile phone she had thrown away earlier. She switches it on for the first time in a month and finds many messages on it.