Hundreds of cuddly mascots are facing the chop after Japan's finance ministry ordered local authorities nationwide to cut back in their use, saying many of them are a waste of public money.

The clampdown comes months after officials in one region ordered a cull of its life-size "yuru-kyara" ("laid-back characters"), after finding that the public has no idea who - or what - many of them are.

Mandarins investigated 105 tax-funded organisations that had created their own yuru-kyara, and discovered "most of them had no clear purpose", a finance ministry report said.

"A majority of them were created for vague 'public relations purposes' and some of them were created just 'because others have introduced mascots'," it said.

Japan has thousands of larger-than-life puppets with cutesy but improbable features, which are used to promote everything from regional attractions to public safety messages.

These include Kumamon - a pot-bellied bear who stumps for a lesser-visited part of southern Japan - and Asahikawa Prison's Katakkuri-chan - a square-faced humanoid with a purple flower for hair, who is intended to soften the jail's public image.

The most successful become national celebrities, spawning a huge range of merchandise that can be worth hundreds of millions of dollars a year.

But the vast majority languish in obscurity, wheeled out by local police forces or libraries at public events where the actor inside the suit must jig jauntily and pose for pictures with a stream of slightly baffled children.

The finance ministry says often little thought appears to have been put into the reasons for having a mascot, or whether it represents value for money.

In one case, a single mascot suit cost Y1.38 million ($A14,565), while in another, a pair that cost Y380,000 ($A4,000) were used for just four events in a year, it said.