BG7RRX According to Article 64 of Japan's "Relaxation Law," using a radio receiver to listen to NHK broadcast programs is not subject to contractual fees.
In other words, you do not need to pay any fees to receive NHK radio broadcasts in Japan using a radio receiver.
Also, I want to mention that the broadcast duration of NHK World Radio has been getting shorter and shorter, and it may soon be discontinued.