MMD-Yamakaze is a tag related to the adult content genre called "MMD" or "Miku Miku Dance," which is a Japanese 3D animation created using the freeware program, "MikuMikuDance." The term Yamakaze refers to a specific character or model used within these animations.
Yamakaze is a fan-created character in the MMD universe, inspired by the popular anime character Hatsune Miku. He is often depicted as a muscular and well-endowed male figure engaging in various erotic activities, appealing to those who enjoy adult animation and content with such themes. The tag "MMD-Yamakaze" would be used to categorize videos featuring this character within the MMD community.