Yuu Watase

A very prolific and well-known Mangaka, Yuu Watase is best known as the creator of Fushigi Yuugi and Ayashi no Ceres, both of which have been adapted into anime. She made her debut in 1989 with the oneshot Pajama de Ojama (An Interlude in Pyjamas) and is predominantly a writer of Shoujo series, although she has recently begun branching out into other demographics, including Shounen (Arata Kangatari) and Yaoi (Sakura Gari). She has also written some novels as well, according to The Other Wiki.

Her first works were typically characterized by love triangles, high levels of melodrama (specially during the original Fushigi Yuugi era), drawn out, almost laughably sappy love scenes, and of course, plenty of Bishonen. On the other hand, when she does decide to go Darker and Edgier, she does so hardcore: Sakura Gari and Ayashi no Ceres have plenty of bishonen, melodrama and love triangles, but the utterly twisted and psychologically driven storyline has had people refer to her as a potential Magnificent Bitch.

She came out as X-gender (the Japanese term for non-binary) in 2019, though she still prefers to use "she" as her main pronoun in English.

Some of her manga works include:

Shinshunki Miman Okotowari
Fushigi Yuugi
- Fushigi Yuugi Genbu Kaiden
Epotrans! Mai
Ayashi no Ceres
Appare Jipangu!
Imadoki!
Alice 19th
Absolute Boyfriend
Sakura Gari
Arata Kangatari

Tropes Commonly Associated within Watase's works:

Art Evolution: Big time. The biggest development was done during Ayashi no Ceres. Her characters, though still similar to each other, have become more rounded. And she deliberately changed her style for Sakura Gari and Arata Kangatari respectively.
Anyone Can Die: Just don't get too attached to any character appart of the lead. Just in case. Literally half the cast of Fushigi Yugi are dead by the end.
Attempted Rape
Break the Cutie
Can't Have Sex Ever: She loves this trope with a passion! In half of her works there's always some reason for the two leads not hooking up. Either the female lead needs to stay a virgin, or one of the characters is cursed, or not a real human, and so on, so on.
Darker and Edgier: Her career went this way starting with Ayashi no Ceres. Case in point, Fushigi Yuugi Genbu Kaiden is much more serious and dramatic than the original Fushigi Yuugi. And then there's Sakura Gari...
First Girl Wins, First Guy Wins
Love Dodecahedron: She is the master of this.
Only Six Faces: Take a look at some of the major male characters from her works, spanning from early series Fushigi Yuugi to her more recent Absolute Boyfriend. Most of them have the same exact face, and their hairstyles are also very similar. Same goes for her female characters, although they're a bit more distinguishable (usually). Although as stated above, she has improved over the years.
- The type of face and hair that repeats more often is the male leads... and since in her free talks she always mentions how she thinks they look handsome, it's pretty clear there's a lot of Author Appeal involved.
Yaoi Fangirl: Has been known to ship her own male characters in the comments sections of her various manga and claimed to be disappointed at not seeing fanfics featuring her preferred couplings. Her foray into actual yaoi surprised no-one.