Extra terrestially moon born, Touya Sagami lives aboard the Space Station Hotel, Anshin [Reassured] and is training his AI robot "Dukky" secretly by removing its limiters. When a group of youths who qualified for the Deegle Space Experience for Youths visits, Touya Sagami has no choice but to mingle with the Earthlings...

Beings known as "Gadoll" suddenly appeared wiping out most of mankind. In an effort to survive the mobile fortress Deca-Dence was built by soldiers known as "Gear" who serve The Power corporation, doing their best to fight them off and survive. One day, Natsume's father and his team set out on another expedition to explore the world...

As with the visual novel game released about 3 years ago this official Anime sequel also takes place just before the prequel's ending about midway through episode 23 so, you could kind of call it an extended version of the original Steins;Gate too. After many attempts Okabe has given up hope trying to reach Steins Gate and savehis...