To understand the significance of the tag, one must look at the macro environment. The COVID-19 pandemic had shifted production schedules globally, but by 2021, the JAV industry had adapted. However, the bigger change was in the viewing habits of international audiences.
Kaito frequented forums where users debated the quality of different "sub groups." In 2021, the demand had spiked. People were stuck at home, and "Javsub 2021" became a high-frequency search term. javsub 2021