The important problem of urban area in Tokyo is the increase price of land. Tokyo University of Agriculture used to rent some lands not to far from university to use as field practice, however, the increase price of lands caused the land owners increased the renting price and wanted to sell. The university now cancelled renting lands and lost their field practice in Tokyo because of high renting price. In addition, Parents in Japan have to pay high tax to government from raising their child. From the reason, parents have to make more money by selling their land and do business. The lands are changed for housing because of increasing in price of area in Tokyo. Agricultural fields change to building. It is difficult to keeps green areas.