The public pension system of Japan provides coverage for all, irrespective of occupation and income. Corporate pension plans provide additional benefits over the public pension in order to meet the diversified financial needs in retirement and play a key role in enriching people‘s life after retirement. The majority of corporate pensions in Japan are defined-benefit type. Consequently, a great amount of attention is paid to benefit rights. Nevertheless, in order to avoid the discontinuation of pension plans due to over-emphasis on benefit rights, Japan introduced a measure under the stagnant economy during the 1990s allowing pension plans to reduce accrued benefits under certain strict conditions, only when the government acknowledges that the sponsoring company will go bankrupt if employers are forced to continue to contribute to the pension plans to the same extent. At the same time, Japan introduced another measure allowing pension plans to use smoothing for valuing its assets in order to avoid temporary market fluctuations. As a result, corporate pension plans in Japan became manageable from a long-term perspective and able to adopt a flexible plan design whilst still ensuring benefit rights.