In this paper, focusing on the minimum guarantee benefit, we estimate the cost of that scheme. In the estimation, we have three cases: 1) the current scheme cost; 2) a high cost case: and 3) a middle cost case, according to the ratio of true zero incomes. Owing to the taxation system in Japan, self employed is often zero incomes with large depreciation. The results are presented here. The peak  of Case2 Male shows approximately USD 150 billion over the period 2060-2070, while the Female variable shows the same level for that period. However, this coincidence is a pure accident. And the peak of Case3 Male shows approximately USD 220 billion, and the Female variable shows approximately USD 300 billion. To avoid such high costs, the DPJ must reform the taxation scheme in advance.