Japan is a country where cannabis products are strictly prohibited. The Trademark Office grants trademark protection for CBD (or cannabidiol) and you can apply for a trademark, but you may be refused. Such trademark applications can be deemed to violate public order and morals. But generally speaking, the Japanese patent office tends to grant the
trademark protection registrations for those trademarks.
Also, in Japan there is the Cannabis Control Act that stipulates cannabis plant and products are strictly prohibited. But there is an exception if it’s THC-free CBD products extracted and manufactured from mature cannabis stems or seeds. That is the only exception where you can commercialise cannabis in Japan. That’s why the Japan Patent Office has granted the trademark registrations for CBD.