On the fifth grade, Netto Hikari was gifted an extraordinary present in the year 20XX, a personalized net navi named Rockman. Although Rockman was smaller in size and had a more mature personality, Netto and Rockman formed an instant bond of friendship. A net navi is equipped to assist its operator from their Personal Terminal, abbreviated PET. People of all ages revel in participating in good-natured duels known as "Net Battles" where they showcase their navi's prowess.