Shy Natsu awakens as part of a group chosen to ensure the survival of humanity. Together, they have to survive on a changed Earth.
Seasons & Episode
Team Summer A banishes Ango and Ryo as Haru and the others mourn the missing Hana. Aramaki leaves the settlement believing she is still alive.
Expecting a trap, Ango and Ryo find and observe Team Summer B, but they are unexpectedly welcomed by the easygoing group.
The two newcomers help Team Summer B. As they get to know the group, Ryo doubts their ability to survive. Ango begins to see Natsu as Shigeru.
The carefree group enjoys life at sea, but Ryo tests their survival skills. Natsu reveals that Team Summer B is for dropouts, angering Ango.
Suspicious, Botan searches Ryo and Ango's belongings while the others look for Arashi. Elsewhere, another survivor learns about the wilderness.
Team Summer B gets stuck in a bed of dense algae. they find a large ship and investigate, but Botan is wary. Stranded, Arashi sees the ship's kite.
The team members are separated after the ship's sudden movement. Arashi makes his way to help as Botan's group makes a discovery.
Ango's hallucinations lead to perilous situations for him and Arashi. Semimaru has a brush with death while Natsu gathers her courage.
A sanctuary in nature becomes a trap for small mammals and humans alike. Meanwhile, an iron-eating bacteria begins to spread throughout the ship.
Fujiko and Chisa reunite with Hana. On the ship, the missiles begin launch prep while Team Summer B learns about Ango's past and the test.
Hana readjusts to other humans. Team Summer B works together to manually disable the missiles, but a series of passcodes complicates the process.
Problems persist in the ship as the spreading bacteria begins attacking. The missile countdown continues as the team makes a mad dash to exit.