Wikipedia
NTT DoCoMo's i-mode is a mobile internet (as opposed to wireless internet) service popular in Japan. Unlike Wireless Application Protocol, i-mode encompasses a wider variety of internet standards, including web access, e-mail, and the packet-switched network that delivers the data. i-mode users have access to various services such as e-mail, sports results, weather forecast, games, financial services, and ticket booking. Content is provided by specialized services, typically from the mobile carrier, which allows them to have tighter control over billing.
Like WAP, i-mode delivers only those services that are specifically converted for the service, or are converted through gateways. This has placed both systems at a disadvantage against handsets that use "real" browser software, and generally use a flat pricing structure for data. Even i-mode's creator, Takeshi Natsuno, has stated "I believe the iPhone (a phone that uses the traditional TCP/IP model) is closer to the mobile phone of the future, compared with the latest Japanese mobile phones."