Yumi is a term commonly used in Japanese adult content, and it refers to the act of having intercourse with an individual who is either named Yumi or has similar physical characteristics. The context generally involves sexual activities, such as oral sex, penetrative sex, or other forms of stimulation. It is often associated with Japanese pornography and anime, where characters with this name or appearance are frequently depicted in erotic situations.
To summarize, the term "yumi" in a porn video tag signifies engaging in sexual activities, specifically with someone named Yumi or who shares her physical traits, which could be interpreted as part of a fantasy scenario within the context of Japanese adult content.