Based on the erotic game by Blue Gale. 
 
The latest series of the Airi storyline finds the three main characters adjusting to their current setting of an open adult relationship. The setting is completely disturbed when Airi and Marina's mother, Kayako (華代子), returns and seeks to "rebuild" her relationship with the stepfather, unaware of him having sexual relations with her two daughters. Also the stepfather is becoming more and more abusive to Airi who has been challenging their relationship with another young lady.

Based on the erotic game by Blue Gale. 
 
Continuing after the events of Oni Chichi: Re-birth... Airi, Marina, and their step father, Takami, leave for a trip to a hot springs resort. But Marina makes last minute plans and just the two of them go. Takami still constantly tries to drug Airi.

Based on the erotic game by Blue Gale. 
 
Airi keeps her relation with her father but he treats her as an object sometimes which makes her angry. One day while watching a movie she gets assaulted giving start to an affair with one of her school's teachers.
 
(Source: Anime News Network)

Based on the erotic game by Blue Gale. 
 
Marina and Airi's mother divorced few years ago and got remarried recently to a young man. While Marina accepts her new stepfather, Airi detests him. Little do they know that really he's a pervert that sniffs their underwear and wants to make them his own by making a love drug that will turn Marina and Airi into sex-hungry sluts. When Airi comes home and notices her schoolmate Sana giving him a blowjob, he sprays the drug on her. Now he will do with them whatever he pleases.

Based on the erotic game by Blue Gale. 
 
Still continues in Oni Chichi's story, this time series Airi and her father are on vacation at his father's hometown in winter. Because the weather is too heavy snowfall makes them become trapped in a cave. At that moment, they met the stealth Tanuki that is on the mountain. 
 
(Source: Nekopoi and Has Been Translated and Edited)

Marina Akizuki