This porn video tag, "asuna-yuuki-hentai", refers to a hentai (Japanese for perverted or perversion) content that features Asuna Yuuki. Hentai is a subgenre of anime and manga that contains explicit adult content and is primarily consumed by an adult audience. The focus on Asuna Yuuki implies that the video would involve her, either as the main character or involved in various sexual acts. Asuna Yuuki is a fictional character from the light novel series "Sword Art Online," which has also been adapted into anime. This tag targets fans of this particular character and the hentai genre in general, looking for explicit content involving Asuna Yuuki.