[Sumomo Dou (Sumomo EX)] Zecchou Kenkyuujo | Orgasm Research Facility [English] [JayCie] [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.

Anal intercourse is a common sexual act tag in doujinshi. It appears across nearly all genres and demographics, from vanilla romance to extreme fetish content. The artistic depiction ranges from realistic anatomy to highly stylized presentations. This tag frequently co-occurs with tags like 'nakadashi' (internal ejaculation), 'big breasts,' and various body-type tags. Some artists specialize in anal content, developing signature techniques for depicting the act. The tag covers both consensual and non-consensual scenarios depending on accompanying tags.

Bondage (緊縛, kinbaku) is a fetish tag covering restraint and bondage scenarios in doujinshi. This ranges from simple rope bondage to elaborate suspension scenes. The artistic treatment varies from realistic kinbaku (Japanese rope bondage) to stylized fantasy restraints. The tag covers consensual BDSM scenarios as well as non-consensual restraint (when paired with 'rape'). Related tags include 'collar,' 'handcuffs,' and 'femdom.'