Therefore, the investigators planned the present clinical study to evaluate the curative efficacy (renal function, QOL) and safety (side effects, complications or occurence of renal cancer) of living renal transplantations between third parties (non-relatives) with restored donor kidneys after the surgical removal of a small size (4 cm or less) renal tumor, in order to acquire necessary clinical data for potential enrichment of the renal donor pool in Japan as well as to develop useful medical care for our patients who are on dialysis for many years due to the renal failure.