The Japanese food “horumon”, also known as “motsu”, is organ meat, giblets, and other types of offal meat.
While these cuts of meat may not be popular in most parts of the world, in Japan they’re seen as a good way to restore stamina and nutrients to the body. This fits in very well with the Japanese mentality of “mottainai” (avoiding wastefulness), which values using almost every part of an animal for cooking.
The Kansai region (Osaka and Hiroshima) is believed to be the birthplace of horumon cuisine in Japan.