How much of the land in Japan is good for agriculture? I would like a relative region, e. g. North, south, northwest, etcetera.

About 15-20 percent is suitable for Agriculture in which the majority is from the North which accounts for about 10-12 percent.

Japan is an island country and it is affected by currents most of the time. These currents cause severe typhoons which hamper a mass agricultural production in the country. This is why Japan relies heavily on imported food products.

we need the diagram to answer this correctly.