Netorare (NTR) is initiated not just by males but females, as well. The female version is known as reverse netorare or gyaku (female) netorare (GTR).
As I said previously, netorare is a controversial fetish, and it is controversial precisely because of human instinct.
Sexual dimorphism in most species has caused males to be stronger and females to be more nurturing, among other traits. These traits allow the males to gather resources to impress mates and for the females to be selective of mates who can provide for them and their offspring.
Cuckolding essentially undermines the male’s worth. It’s one matter if he loses his resources or the female willingly leaves him to choose another partner, which are potentially devastating in their own ways; it’s another to have a male (or female) take his partner against her will and in spite of his resources.
And yet, the same cannot really be said of gyaku netorare.
Let’s compare the ratings (as of the time of the writing of this post) of a few titles on MyAnimeList featuring each sub-genre:
Otome Dori (2012): rating of 6.08. Mesu Nochi Torare (2013): rating of 6.14. Ore wa Kanojo wo Shinjiteru! (2011): rating of 6.48.
Genkaku Cool na Sensei ga Aheboteochi! (2015): rating of 7.28. Cafe Junkie (2008): rating of 6.99. Fukubiki! Triangle: Miharu After (2010): rating of 7.29.
Now granted, netorare commonly coincides with themes of r**e and blackmail, whereas fans consider gyaku netorare to be mostly or completely vanilla. There are also other ratings-influencing factors such as the producers and the animation studios that worked on each title.
Still, there is a noteworthy discrepancy between the two groups of titles. Some edited, general comments on MAL between them can give us some insight:
“Hope the guy takes a gun and shoots all these old men down.”
“I cannot express my feelings about this OVA in words. It’s so damn depressing and retarded.”
“This has to be the worst hentai I’ve ever seen. […]”
“Best PoRo hetai by a country mile. Great girls with nice personality. […]”
“WOW is friggin hot hentai!! Seriously man!!”
“This hentai will make you feel like you was in the MC’s shoes.”
Hentai fans predominately are male, so consider human instinct from a male’s perspective.
As previously stated, hentai fans generally deem netorare to be controversial because it undermines the male and his resources.
Gyaku netorare essentially reverses the roles between the sexes. That’s partly why it’s also known as reverse netorare. Men become the coveted and women become the coveters to the point that they take men away from their lovers. That’s a favoring change of pace for an audience which is predominately male because a girl gets to love the main character either way.
Even then, gyaku netorare typically does not have co-themes of r**e, blackmail, and so on. Likely, this is because the hentai market itself is a major factor. Maybe such a hentai would not sell well in Japan. There is an escapist element to all of this, so perhaps the addition of dark themes would break the immersion and not allow this genre to work at its best. While it can be featured in hentai of this genre, reverse r**e is more of a sub-genre of or at least related to femdom which generally is vanilla or mostly so, meaning it’s compatible with reverse netorare.
Gyaku netorare, while also dealing with human instinct as netorare does, takes a somewhat different approach. This can be explained through the differing human instinct through the sexual dimorphism of the genders.
Dominance in males and hypergamy in females in real life exist ultimately so the species continues to propagate, and propagation occurs through intercourse in a sexually dimorphic species. The limited number of eggs and the length of pregnancy for a female means they need to be as selective as possible in order to ensure the healthy survival of themselves and their offspring. Meanwhile, the nearly limitless number of sperm and lack of child-birthing translates to a higher libido for males which encourages them to gather the resources to have female partners and to have intercourse.
Look at gyaku netorare this way: it’s a forced, successful harem of sorts. It allows the male lead, typically acting as an insert for the viewer, to skip the step of having to gather resources. It just gets right to the female partners. This is common in vanilla hentai, as well.
However, here, the harem females’ competition among themselves is not limited just to words and the occasional challenge, whatever it may be. It goes further. Within the given hentai, at least one female will successfully steal the male, who is already in a relationship or at least has feelings for a female and/or vice versa, from another and go all the way with him.
R**e and other dark, related themes usually do not come into play. This is because, as an example, the male laments that the first female does not accept him even though the viewers at least know she does admire him, and the second female whispers sweet nothings of her own desire to love him and to want him to forget how the first has hurt him. Or the first is already in a relationship and the second decides to take him anyway.
In the first, somewhat unrequited instance, the second female, with her male-like candidness, becomes a nurturing provider of love. She rewards him with her love, and nature soon rewards them both with dopamine. The first female next commonly accepts her feelings, re-takes him, and nature soon rewards them both with dopamine, also. The two females then may decide (to continue) to make love and not war and to share him.