While Wii U's "ordinary online services" will be free, Nintendo may ask users to pay for deeper features.
Nintendo president and CEO Satoru Iwata told shareholders: "We cannot promise that Nintendo will always provide you with online services free of charge no matter how deep the experiences are that it may provide.
"But at least we are not thinking of asking our consumers to pay money to just casually get access to our ordinary online services."
Last week Iwata ruled out an Xbox Live-esque subscription model for Wii U, stating that it wasn't appropriate for Nintendo's audience.
"We have a wide variety of consumers, from the ones who enthusiastically play video games to those playing more casually, who are not always interested in them but try to play a game only when it has become a public topic or play it just during certain periods, like a year-end season and summer vacation," he said.
"We therefore believe that services which ask our consumers to obtain paid memberships are not always the best."