Wolves (狼 ookami) are mammals often identified as the gray wolf, scientifically known as Canis lupus. Although a few other animals in the Canis genus have been named wolves as well. The gray wolf is widely dispersed throughout the world wherever humans live. Like humans, because wolves are so widely distributed across the world, they come in various color, shape, and size despite being the same species.
The domestic dog (犬 Inu) is a sub-species of gray wolf which evolved alongside humans. Scientifically known as Canis lupus familiaris, dogs have lived together with humans since the prehistoric era. They were originally born to assist humans in hunting and gathering, but have become normal pets in the modern era. They should however not to be confused with wild dogs which are separate species of animals.
The yamainu (ヤマイヌ/山犬 Mountain Dog), more commonly known as the Japanese wolf (日本狼 Nihonookami) are one of two extinct sub-species of gray wolves that were native to the Japanese archipelago. They were scientifically known as Canis lupus hodophilax and is officially classified as extinct since the last animal's death in 1905. The Japanese wolf is known to play a major role in Japanese folklore and mythology.
Yamainu are animals that still exist in Gensokyo and are living in the mountains as shown in Oriental Sacred Place chapter 16. Marisa Kirisame states that because of the of the abnormal weather causing a shortage of supplies, the wolves are attacking humans. it would also appear that normal stray dogs wander around Gensokyo, just like the yamainu.
- Examples: Momiji Inubashiri (Youkai White Wolf), Unnamed Okuri-inu (Youkai Yaminu), Kasen's Dog