So I ended up on the Only One Name TV Tropes page the other day, and was surprised to see that the Real Life section only mentions one mangaka, when there are literally hundreds of examples of monopseudonymic (pseudomononymic?) artists on Dynasty alone. Hell, there are even some who use numbers as pen names. (Though that's a different trope.) Just throwing this out there in case anyone here feels like editing it...
Also, I've noticed that the trope tends to be inverted by mangaka adopting extra names when they go "legit": Taiyaki, for example, has become "Nakamura Taiyaki" for the purposes of official English editions. Even though that's not a proper Japanese name at all, being the equivalent of something like "Cornish Pasty Johnson".