[Yakitate Jamaica A (Aomushi)] Hatsujou Kiken Chitai (Oozora Subaru, Nekomata Okayu) [Digital]

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.

Futanari (ふたなり) refers to characters with both male and female sexual characteristics — typically female-presenting characters with a penis. This is a significant genre in hentai with its own dedicated audience. The tag covers a wide range from characters with both sets of genitalia to characters who are essentially female with male genitalia. Artistic treatment varies from realistic to highly stylized. Related tags include 'males only' (for futanari-only content) and 'yuri.'

Collar (首輪, kubiwa) is a costume/accessory tag indicating characters wearing collars, often in a BDSM context. Collars symbolize ownership or submission in kink scenarios. The tag covers both decorative collars and functional bondage collars. It frequently appears alongside 'bondage,' 'femdom,' and 'pet play.'