[Haitoku Kenkyuujo (Kuro Yoroi)] Gedou Shiokinin [Digital]

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.

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.'

Double penetration (DP) is a sexual act tag indicating simultaneous penetration of two orifices. In doujinshi, this typically involves vaginal and anal penetration simultaneously. The tag is often found in gangbang or multi-partner scenarios. Artists use various techniques to depict the act, often with emphasis on the character's reaction. Related tags include 'gangbang,' 'anal,' and 'multiple male.'