終末トレインどこへいく？

After a mysterious rollout of "7G" technology reshapes Japan overnight, high schooler Shizuru Chikura sets out to find her missing friend Youka by taking an old, abandoned train out of their hometown of Agano, where anyone over 21 has already turned into an animal. An elderly conductor gets the train running again, and classmates Nadeshiko, Reimi, and Akira join Shizuru for a ride into territory none of them can predict.