Over the past few years, Japanese consumers have, as in markets the world over, abandoned their old phones for newer, shinier smartphones like the iPhone.

But one demographic subset have remained faithful to their old flip phones – and, ironically, it’s Japan’s philanderers.

Those who like to play away are snared in an enduring love affair with one particular series of Fujitsu mobiles which feature a range of privacy features that hide calls and texts.

Fujitsu’s ageing F-Series flip phones – nicknamed the “uwaki keitai” or “infidelity phone” – are the cellphones of choice for customers who believe newer versions are not as discreet at hiding their affairs.

They feature a nearly invisible “privacy mode” that hides missed calls, e-mails and texts from any contacts designated as private.

The only indication that such a person has got in touch is a subtle change in the colour or shape of the battery level icon.

A secret combination of keys is needed to turn off the privacy mode, revealing the concealed calls and messages and making voicemail available.

A Japanese pick-up artist and blogger, Bakanabe, said he used the phone because women he was seeing might try to check his phone for strange calls or e-mails.

“With Fujitsu’s privacy mode they can’t see that information at all. The key is to give the impression that you’re not locking your phone at all,” he said.

– Daily Mail