Touring After the Apocalypse, Vol. 2

Youko and Airi's next stop is Umihotaru, a rest stop in the middle of Tokyo Bay famous for its nighttime views--but with the Aqua-Line tunnel from Kawasaki flooded, they're forced to take a huge detour all the way to Kisarazu! On the way, the two swing by Akihabara to investigate a mysterious radio signal. Could someone still be alive there...?