A group of people with debts filed simultaneous lawsuits Friday in 12 prefectures against consumer loan companies, demanding that the lenders return a combined 700 million yen they collected by charging illegally high interest rates.

With the inclusion of those who are seeing court-mediated settlements with the firms and others who plan to file such suits with courts in the near future, the number of plaintiffs is expected to reach more than 700, according to Cre-Sara Hirenkyo, a nationwide liaison council working on behalf of victims of loan sharks.

The plaintiffs borrowed money from major consumer loan companies at above the maximum 15 percent to 20 percent interest rate set by the Interest Rate Restriction Law and paid exorbitant interest over long periods of time, council officials said. One person had paid excess interest amounting to nearly 6 million yen, they said.

Another law regulating interest rates stipulates that charging rates over 29.2 percent can constitute a criminal offense.

However, the plaintiffs said they were confident that recent judicial precedents have established that the interest that debtors are legally required to pay is different.