As the members of the Mutoh family go about their daily lives, a series of powerful earthquakes begins wreaking mass destruction throughout Japan.
With the waters rising, the Mutohs and their neighbors Nanami and Haruo decide to abandon the shrine where they've taken refuge and leave Tokyo.
Tragedy strikes, but the survivors continue making their way westward. Kite, a popular Estonian YouTuber, decides to join the group.
The group shelters at a grocery store, but earthquakes force them onward. They escape with the owner, picking up an English hitchhiker along the way.
The Shan City community welcomes the travelers with open arms. The group's leader communes with the dead, causing a rift between Ayumu and her mom.
The commune imprisons Kunio after the escape attempt. Ayumu realizes that the old man is using Morse code to try to share a desperate warning.
The survivors reach a port where boat evacuation is in progress. Ayumu is allowed aboard due to her athletic potential, but no one else makes the cut.
The Japanese archipelago begins to sink. The group escapes aboard a fishing vessel, but they're forced into the lifeboats after it's damaged.
The raft survivors rendezvous with Kite and Onodera, then head for the coordinates of a research facility: it may hold data that can save Japan.
Onodera's data contains a map showing that parts of Japan may resurface. For the survivors, rescue hinges on reconnecting to Kite's internet balloon.