The much-awaited number portability started Tuesday, with mobile carriers offering new gadgets and services to woo customers.
Users can now take their telephone numbers with them when they move to another service provider, although their mobile e-mail addresses will have to change.
"We have been preparing for this moment, improving music functions and designs on newly launched mobile phones," said Hirofumi Morozumi, general manager of consumer business at KDDI Corp., the No. 2 carrier.