Ochiru Hitozuma

I'm in love

—Haruki Nagisa.

A 2011 Hentai Visual Novel.

Haruki Nagisa’s parents were killed in a car accident leaving him adopted into the Natsume family, but Haruki has a dark past that none of them knows. As it turns out Haruki’s father was a highly skilled trainer within a prostitution ring called Under Eden, and Haruki wants to follow on his steps. His first target is his own adoptive mother Sayoko, who he meticulously drugs for years along her husband to make them stop having sex, before seducing her into adultery.

Ochiru Hitozuma or Fallen Wife is a visual novel created by Black Lilith. Unlike most of its compatriot, it takes place in a more mundane setting with less fantastical elements. Nevertheless, it is confirmed to take place in the same universe as the Taimanin Asagi Universe, with aspects of this game being shown in other ones, most notably Under Eden, which is the main setting of Taimanin Yukikaze.

Published by Anime Lilith. Directed by Mijou Suu.

Tropes used in Ochiru Hitozuma include:

All Women Are Lustful: Played with. The main female characters here actually have pretty normal sex drives. Its not until they become addicted to Haruki's drugs are they turned into this.
Alternate Timeline: Going based on Under Eden's website (although the canonicity is dubious at best) its implied that this game takes place in an alternate timeline to Taimanin Asagi, where the bad ending routes of Taimanin Yukikaze occurred (most likely the Fallen Rinko route) along with Taimanin Murasaki's Escape route.
Babies Ever After: In the "A New Family" ending, Haruki impregnates both Sayoko and Reiko pregnant.
Bad Guy Bar: Paradise, which is a bar in Morino City that operates as a swingers club. The establishment is actually a front for Under Eden. Members of Under Eden would gather here to run their human trafficking operations and show off their newest slaves.
The Bad Guy Wins: Surprisingly, there actually is no "bad ending" for Haruki. No matter what ending the player gets, he always comes out on top.
The Cameo: Many of the characters from the Taimanin Asagi franchise make brief appearances on the Under Eden's website.
Child by Rape: How Sayoko explains to her husband that she got pregnant despite him not remembering any sexual relationship, saying he raped her while drunk.
Children Are Innocent: The main reason of why Haruki manages to pass under everyone's radar is because everyone thinks so in-universe. No one thinks he has bad intentions or could be associated with a sex trafficking ring thanks to his age, no matter how conspicuous he appears sometimes.
First-Name Basis: Ryouko is not on one of these with her division boss, what makes her alert him to drink less coffee.
Friend in the Black Market: The manager of Paradise serves as this to Haruki, as he supplies him with the drugs, devices, and sometimes even henchmen needed for Haruki's plans to "train" the women that he is targeting.
Hero Antagonist: Ayase Ryouko, a police detective who is investigating Under Eden and threatens to expose Haruki's criminal associates.
Hopeless Suitor: Takashi's attempts to seduce Reiko do nothing to appeal to her, to such an extent that Haruki, once he begins to target her, sees zero problem with both staying alone together for a prolonged period.
Intergenerational Friendship: The manager of Paradise, which is implied to be much older than Haruki, is the only person Haruki genuinely can call a friend. That is thanks to their common interests in degrading and corrupting women.
Karma Houdini: Regardless of what ending the player gets, neither Haruki or the Manager actually pays for their crimes.
Light Feminine and Dark Feminine: The two main female leads, Sayoko and Reiko, respectively.
Making Love in All the Wrong Places: Haruki and Sayoko have sex on a public park at night, the male bathroom of the school where Haruki goes to, and a public beach.
Multiple Endings: Like most Lilith-Soft games. This game has a total of 5 different endings.
Parental Incest: Haruki lusts after his adoptive mother Sayoko.
Reluctant Fanservice Girl: Haruki forces his targets to dress or even undress in public, making them very embarrassed.
Sequel Hook: In the game's canon ending, Sayoko and Reiko have fallen completely and have become Haruki's obedient slaves. Despite both of them being pregnant with his children, they were to able to successfully lie to their respective husbands and claim that the children are theirs. Haruki and his criminal associates were able to evade Ryouko's police raid on Paradise by getting rid of any incriminating evidence, which put a blemish on Ryouko's reputation. Later Haruki orders Reiko to text Ryouko to ask her to meet up at Cafe Natsume. The story ends with Haruki waiting for Ryouko at the cafe with the implication that he plans to turn her into his next Sex Slave.
Sex Slave: The fate of the Sayoko and Reiko in all possible endings. Ryouko might also suffer this fate as well depending on which ending the player gets.
Shameless Fanservice Girl: How Haruki's victims look like to observers, since he forces them to dress in skimpy ways.
Shared Universe: With the Taimanin Asagi franchise. A rather strange choice on Lilith-Soft's part given the more mundane setting of this game, compare to the Urban Fantasy setting of the Taimanin series (and this was before the retcon that most, if not all, Lilith-Soft games exist in the same multiverse). Although what ties the games together is the human trafficking ring, Under Eden, that served as the villainous faction of Taimanin Yukikaze and, technically, this visual novel.
Stripperific: The clothes Haruki makes Reiko wear after blackmailing her exposes a lot of skin.
Weirdness Censor: Sayoko's husband saw her and Haruki having sex right by his side on the couple's bed, but dismissed it as a weird dream for it being so completely odd.
Villain Protagonist: Nagisa Haruki, considering that he wants to follow in his father's footsteps and become a "trainer" who turns people into Sex Slaves.
Your Cheating Heart: Sayoko's drama involves the fact she thinks she is cheating willingly on her husband, unaware of Nagisa drugging her to make her feel an extreme amount of libido.