Connection, Friend (接続, 仲間) is the 12th and final episode of the anime adaptation.
While exploring the submarine, the girls inadvertently synchronize their camera to the submarine's computer and it displays their photographs, plus those Kanazawa took before giving them the camera. Among the computer files, they find videos of people and past events, including the war which led to the destruction of humanity.
Later, a larger Nuko resembling the pillars they encountered earlier, suddenly appears and swallows Yuuri. Chito pursues the creature outside the submarine and finds Yuuri safe as the creature had only wanted to ingest her radio. The creature then explains that their purpose is to consume and stabilise unstable energy, like power sources and weapons. It says that life activity on Earth will eventually come to an end.
It explains that their work in the city has finished as more creatures emerge from the missile tubes. It says that Yuuri and Chito are the only humans they have detected up to this level. Slowly, the tops of the creatures expand and open like mushrooms, then they begin to drift upwards together like dandeloin seeds taking Nuko with them.
With the submarine now completely shut down, Chito and Yuuri continue their journey towards the top level of the city, with a new sense of camaraderie and their and importance to each other.