Yumejoshi (妊女子) literally means "dreaming girl" in Japanese. The term emerged from the tradition of "dream novels" (妊小説, yume shōsetsu), a style of Japanese fan fiction popular from the 1990s onward in which the reader could replace the protagonist's name with their own and experience the story alongside beloved characters. A yumejoshi is a female or fem-aligned fan who engages in this kind of self-insertion, imagining a romantic or emotional relationship with a fictional character from anime, manga, or games. The masc-aligned equivalent is yumedanshi, while the gender-neutral term is yumejin or simply "yume." The practice spread to Western fan communities through Tumblr in the 2010s and exploded on TikTok in the early 2020s, where short explainer videos and F/O aesthetic edits brought the vocabulary to millions of new fans.

An F/O, short for Fictional Other, is the specific fictional character someone ships themselves with in a yumeship. The relationship can be romantic, platonic, or familial. A comfort character, by contrast, is a broader term for any character who provides emotional grounding and solace to a person, not always through self-insertion and not always in a romantic context. Someone might have a comfort character they simply feel safe watching or thinking about, without imagining a direct relationship. The "he's not real but..." meme format resonates with both communities because in both cases the fictional character occupies emotional real estate in a very real, very meaningful way, even if the relationship exists entirely in imagination and fanfiction.

Research increasingly validates what yumejoshi and self-shipping communities have long known: parasocial and fictional emotional connections can be psychologically beneficial. A 2024 paper presented at the ACM CHI Conference on Human Factors in Computing Systems identified self-shipping as one of four major fan-defined parasocial relationship types gaining measurable popularity, alongside simping, kinning, and shipping. A 2024 study in the International Journal for Multidisciplinary Research found that parasocial interactions with anime characters provide emotional regulation and stress relief. While fictional relationships should not completely replace real human connection, engaging with a comfort character or maintaining a yumeship is widely regarded by researchers as a normal extension of the human capacity for narrative empathy. Many people use their F/O as a safe emotional anchor during difficult periods.

Every year, a widely anticipated poll circulates among Japanese Twitter/X users to determine the top 100 fictional male characters most beloved by yumejoshi and self-shippers. The results are tracked, debated, and celebrated internationally as a kind of fandom census for the yumejoshi community. In the 2025 results, characters from Twisted Wonderland featured prominently, with Ace Trappola breaking into the top 10, Skully J. Graves holding a strong position for the second consecutive year, and Trey Clover maintaining a record of appearing in every annual poll since 2020. The results spark enormous conversation each January, with fans comparing placements, noting upsets, and defending their F/Os with passionate dedication. It is one of the most visible annual traditions in the global yumeship community.

"Sharing NG" (NG = Not Good) is a boundary signal used in yumejoshi and selfship communities to indicate that a fan prefers not to interact with "doubles," meaning other people who have the same F/O and are also in a yumeship with the same character. It reflects a desire to keep the emotional relationship private and undiluted. The opposite is "Doutan Kangei" (同担欢迎), which means the fan is happy to connect with others who share their F/O. A flexible stance called "mirror-sharing" means the person adapts to whoever they are interacting with. These distinctions are genuinely important to community etiquette. Before engaging with another yumejoshi or yumedanshi online, checking their bio or pinned post for sharing preferences is considered basic community courtesy.