Shy Natsu awakens as part of a group chosen to ensure the survival of humanity. Together, they have to survive on a changed Earth.
EPISODE 1
Spring Begins
Along with three others, Natsu wakes up without an idea of what has happened; the quartet reaches an island to try to figure out a way to survive.
EPISODE 2
Insects Awaken
Convinced that Botan has kidnapped them, Natsu and Arashi sneak out of camp and run into another survivor; Botan reveals what she knows.
EPISODE 3
Light Snow
Natsu's clumsiness indirectly leads Team Summer B to the rest of the group; her memories help them figure out their location -- and their next moves.
EPISODE 4
Autumn Begins
Arashi, Natsu and Semimaru stumble on the Team Autumn settlement in the former Kobe region; they seem to be thriving, but their leaders are tyrants.
EPISODE 5
Heavy Snow
In the ruins of Tokyo, Natsu, Arashi and Semimaru meet Team Winter's sole survivor; Team Spring reaches Mount Ogino Fuji and finds Natsu's message.
EPISODE 6
Grain Rain
Aramaki joins Team Spring, despite Fujiko having doubts; Hana decides to search for Arashi after hearing that Aramaki met someone who fits his description.
Nao Toyama
Jun Fukuyama
Katsuyuki Konishi
Yoko Somi
Kana Asumi
Akira Ishida
Yukio Takahashi
Yoshiki Sakurai