The world's first third-generation mobile phone service has been hit by a glitch in its e-mail service.
Operator NTT DoCoMo says a server problem means e-mails were unavailable for 18 hours from yesterday afternoon.
The pioneering service - offering high-speed Internet connections on videophone handsets - was launched on Wednesday.
The company says the disruption stemmed from a server fault in one of its installations in Yokohama, near Tokyo.
Spokesman Mr Hiroto Nakagawa says the problem has now been fixed and the service is operating properly.
He says the limited roll-out, involving only 3,300 users in the Tokyo area, is intended to allow problems to be ironed out before a full consumer offering.
The company originally promised a service for the whole of Tokyo by May, but was forced to postpone this until October after encountering recurring software problems.
PA