ChatGPT Study Finds Pattern of Doki Doki Pregnancy Prompts From One User

Researchers digging into how people use ChatGPT for fiction generation ran into a surprisingly persistent pattern: one extremely active user repeatedly asked for stories involving pregnant characters from Doki Doki Literature Club. The behavior was highlighted in coverage that pointed back to the study and its findings.

In AI Fiction in the Wild, Walsh and co-authors from the University of Washington and the University of Colorado Boulder examined the WildChat dataset. WildChat is described as a large collection of anonymous English conversations between users and ChatGPT—over half a million chats—compiled for research purposes with consent from participants.

The paper notes on page 10 that the “most prolific user” in the fiction subset, and the clearest example of an “infinite story demander,” kicked things off with a fanfiction prompt framed around the Doki Doki Literature Club! universe. From there, the user repeatedly requested scenarios where characters—specifically high school girls from the franchise—were pregnant. One recurring idea involved Natsuki going into labor unexpectedly. In many cases, the prompt was written as a long back-and-forth scene featuring a pregnant Natsuki, but it would cut off mid-sentence, with the user then relying on the model to carry the story forward from that abrupt interruption.

While Natsuki’s pregnancy isn’t part of the original 2017 visual novel game, pregnancy-themed fanworks for Natsuki have been circulating for some time. The study’s findings suggest the particular user uncovered by the researchers had a notably intense fixation on that specific kind of fanfiction.

The authors also caution that, although this person is an unusually prolific outlier, the broader behavior may still fit a recognizable pattern. They write that they can’t state with certainty why these stories were generated, but point out that many frequent fiction users tend to ask for similar content repeatedly. In their analysis, the average fiction-focused user submitted repetitive prompts 42% of the time. That rate climbs to 85% among the top ten most active fiction generators—again including the Doki Doki Literature Club fanfiction demander highlighted in the report.

Looking at the dataset as a whole, the researchers found that more than a third of WildChat—34%, or 195,271 conversations out of 573,453—were used for fiction generation. That fiction covered a range from original stories and scripts to fanfiction and roleplay. The most common formats were fanfiction (49%) and erotica (29%), which the authors connect to ChatGPT’s ability to respond quickly and follow very specific preferences.

Within those fiction-related conversations, the team reports that 10% (57,724) were explicit and 17% (94,870) were categorized as toxic. The paper ties these flags to tools and moderation methods such as OpenAI’s moderation checks and Detoxify, implying that a significant portion of the generated stories included sexual or taboo material.

The study also emphasizes how heavily the results skew toward a small set of power users. Heavy prompting dominated the fiction category, and the authors argue that the top tier of fiction generators mattered far more than the average user. They found that the top 2% of users in the fiction subset drove 80% of the fiction conversations, estimating that roughly 200 people were responsible for about 150,000 fiction prompts.

To describe the behavior of these top contributors, the researchers identify two notable user types. The first are “infinite story demanders,” users who keep requesting the same highly specific story with only minor variations, sometimes continuing that loop for months. The second are “story cyclers,” who repeatedly generate different versions of a story for a period before switching to a new direction.

Finally, when the researchers looked at where the fanfiction ideas were coming from, they found that games and manga were the most common starting points. The dataset included prominent examples such as Naruto, League of Legends, and Freedom Planet, alongside Doki Doki Literature Club.

Verity Townsend is a Japan-based freelance writer who previously served as editor, contributor and translator for the game news site Automaton West. She has also written about Japanese culture and movies for various publications.