(Tenmusume) is a well-known Japanese adult site that specializes in "amateur" style content and themed shoots. : This is the release date in format. In this case, it corresponds to November 11, 2010
The JAV industry is a massive part of Japanese entertainment exports. Studios like 10musume cater to a specific "idol" culture, where the personality and "cuteness" (kawaii) of the performer are just as important as the content itself. This specific video from 2010 represents an era where digital distribution was beginning to overtake physical DVDs, leading to the highly specific naming conventions seen today. 10musume 101111 01 hd allrarl