Berry is a girl living in the data-managed city of Tom Sawyer Island. Her hobby at the moment is trying to catch Phantom Zero, who's believed to be behind the cases of Love loss known as the Zero Phenomenon. One day, when she heads into town to get the broken Deco in one of her eyes fixed, Berry runs into a kid who seems like a ghost, due to being unable to be seen with Deco. Suspecting she may have finally found the Phantom, Berry begins her chase.

Hack is being held at the customer center under suspicion of being Phantom Zero, where she's questioned about the crime of forcibly erasing Love. Meanwhile, Berry learns from the mysterious Finn about how he and his comrades are ghosts, citizens who live in the city despite not being registered. Finn is skeptical that a fellow ghost would have helped Berry, and obtains the data on Phantom Zero from the paper plane device of Hack's that Berry brought.

Berry catches wind of a ramen cart that nobody knows the location of. In order to find it, Watson begins checking rumors from all across the island. Berry suggests that the detective club search for the cart, but the other members aren't interested. As Berry and Watson investigate the rumors, Watson receives a tip on the location of the cart. In pursuit of ramen, Hack, Berry, and Watson set out to find it.

When Finn was young, his family lived in a slum where garbage tended to be dumped. One day, his brother brings him an older model of Deco that should be easier for Finn to use due to his Deco-Sickness. With it, Finn accidentally discovers that the local purification systems are broken. Believing this is what has caused his home to become polluted, he uses the Deco that he got from his brother to request that the customer center fix the purification system. But because he isn't registered as a citizen, his login is flagged as illegal, which leads to his request not being answered.

After being suspected of being Phantom Zero, Berry and the club use Deco disguises in order to escape. Meanwhile, the customer center is in a frenzy, thanks to reports of Phantom Zero that they're receiving from all over the place. They dispatch a search team to the slums. Finn and the detective club take shelter in one of Finn's secret hideouts, with Finn stating the only way they can clear their names is to head to the mysterious location known as Mark Twain, and apprehend the true Phantom Zero.

A young girl awakens in a empty white space. She's enjoying a happy life with her parents, staring out at her pet peacock. But then, from out of nowhere, Berry appears. The girl is surprised, and attempts to run away.