(Kagaku Seiki no Cafe Terrace 9) [Kyouizon Smile (Ushi Kousen)] Hobetsu Renko (Touhou Project)

Sole female indicates that a gallery features exactly one female character throughout the entire work. This tag is important for readers who prefer focused, intimate scenarios rather than group dynamics or harems. It doesn't imply anything about the number of male partners — a sole female gallery can feature one male partner (sole male) or multiple. The tag helps distinguish between different relationship dynamics and is commonly paired with tags like 'sole male' for one-on-one scenarios or 'multiple male' for gangbang-type content. In terms of narrative structure, sole female works often develop a single relationship or encounter in depth rather than juggling multiple characters.

Sole male indicates a gallery features exactly one male character. Combined with 'sole female,' this creates the classic one-on-one pairing. With multiple female characters, it creates a harem scenario. This tag is useful for filtering based on the reader's preferred dynamic — whether they want focused monogamy-style content or one male with multiple partners. The tag doesn't specify the male character's role or prominence; he could be the protagonist, a side character, or even a reluctant participant depending on the genre.

Ahegao (アヘ顔) refers to the exaggerated facial expression of ecstasy commonly depicted in hentai. The face is typically shown with rolled-back eyes, protruding tongue, and flushed skin. This visual trope has become iconic in adult manga and is used to indicate intense pleasure or overstimulation. The tag covers both subtle and extreme versions of the expression. It frequently appears alongside tags like 'big breasts,' 'nakadashi,' and 'multiple male.'