Chito and Yuuri have arrived at the highest stratum, but their journey will not be over until they reach the very top of the city. Along the way, they continue to explore the evidences of humanity's innovation and growth through the ages, now nothing more than crumbling ruins. Having learned what they can about the past, the girls embark on the final leg of their tour.

Distant lights illuminating the darkness pique Chito's and Yuuri's curiosity, so the two hop aboard their beloved Kettenkrad and head for the horizon. What they find may not be what they were looking for, but the surviving fragments of civilization are enough to keep them going.

Even after a mysterious life form tells Chito and Yuri the end of the earth is near, still they continue their everyday adventures together, traveling slowly toward the city on the top-most layer. Their days pass as usual: with the goal of food and making it to tomorrow, with a little bit of relaxing and kicking-back, of course.