[September (Sanku)] Boku wa Osananajimi no Inu. Osananajimi wa Senpai no Mesuinu.

Big breasts (巨乳, kyonyu) is one of the most iconic body-type tags in doujinshi and manga. It refers to female characters with notably large, exaggerated breasts that often serve as a central visual element. Artists typically emphasize size, weight, jiggle physics, cleavage, and breast-focused activities like paizuri (titjobs) and breast play. This tag spans nearly every genre — from vanilla romance to hardcore fetish content. The artistic treatment varies widely: some artists favor realistic proportions while others push into exaggerated territory. Related body-type tags include 'huge breasts' for extreme cases, 'small breasts' for the opposite aesthetic, and 'paizuri' for breast-focused sexual acts. The tag often appears alongside 'sole female' and 'nakadashi' in heterosexual content.

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.

Nakadashi (中出し) literally means 'internal ejaculation' and refers to creampie scenes in doujinshi. It's one of the most common sexual act tags, appearing in over 120k galleries. The tag covers vaginal internal ejaculation specifically. In narrative terms, nakadashi often serves as a climactic moment and may be tied to plot elements like pregnancy, impregnation, or relationship escalation. Artists frequently emphasize the visual aspect with detailed internal views (often using x-ray techniques). Related tags include 'impregnation,' 'creampie,' and 'internal cum shot.'