As Japan lowers the age of adulthood by two years from 20 in April, among the many new freedoms and responsibilities facing 18- and 19-year-olds will be the ability to enter into consumer contracts without parental consent.

They will, for instance, be able to take out loans or make investments, purchase cellphones or buy various services over the internet.

But stripped of the protection of the "right to cancel a minor's contract" after the fact by either the person in question or a guardian, those with little or no experience as adults could be particularly susceptible to scams, experts fret. The key to protecting them, they say, will be preventing such problems before they happen.