A few days ago I received mail from JOGB NHK Radio 2. I heard them on January 7, 2020 on 873 kHz. Besides a few stickers and 3 postcards, there was also a personal letter with the message that they do not send QSL / confirmation cards. I think it is special that they also sent back my homemade QSL card and more or less confirmed it with a stamp from their mascot!