The year is 200X, an age where everything is covered with computer networks, and everyone in the world has a 'PET' mobile terminal. Hikari Netto, a grade school student at Akihara Elementary, is in perfect harmony with his NetNavi, Rockman, and is obsessed with Net Battles. But then, he gets caught up in an incident involving World Three (WWW), a criminal organization that stages cyber-terrorist attacks. Finally, the Ministry of Science is taken over, and Netto's father is taken hostage. In order to save his father and stop WWW's plan, he confronts the Dream Virus, the most powerful computer virus fused with the 'Ultimate Program.'