Their virtual pet dog Densuke goes missing when he falls into an abandoned zone of cyberspace occupied by an illegal.
After separating the illegal from Densuke, Isako failed his attempt to "unlock" the organism with her key, causing nearby cyberspace to rupture.
A cyber battle frenzy breaks out at school between Isako, Fumie, and Daichi Sawaguchi's group, the Daikoku Hackers' Club.
While Isako is the ultimate victor with Daichi's group completely subdued, Fumie manages to steal a piece of data from Amasawa that is totally corrupted with exception of the word "Michiko".
Under pressure, Haraken reveals to Yasako and Fumie his familial connections to the administrators of Searchmaton and his motive for investigating viruses and illegals.
The kids spend a dark and stormy night at school telling ghost stories and playing spooky cyber games.
Yasako, utilizing a communication device devised by Megabaa, becomes heavily engaged in a god game-like relationship with the developing civilization.
The protagonists agree to aid Denpa in relocating a docile plesiosaur-type illegal, which he had previously been raising in an obsolete space now scheduled for reconstruction.
Deducing that the place from her memories was a virtual space deleted by Searchmaton, Yasako heads home as Takeru reports the day's events to a mysterious collaborator.
For their research project, Haraken and Fumie find early records of cyber users who have passed out and reported hallucinations of "the other side".
It is revealed that Coil Domain, Michiko, Imago and Kirabugs are remnants of an experiment gone awry, covered up by the Megamass conglomerate.
Nekome, driven to reveal true nature and history of the cyber technology, tries to convince Isako to join her brother in Coil Domain using Densuke as a portal.
Aided by her friends and family she must fight Michiko's grip on Isako and to avoid Nekome's desire to dispose of her consciousness.