Basically, a sister trope to World of Buxom, only not necessarily boob-centric. In a World of Buxom, every woman starts out at a G-cup around puberty and works their way up (see, Eiken) well this is similar. In a world of Hotness, the most average, plain girl-next-door looks like a Victoria's Secret model...the ACTUAL models look like you should be hearing harps and seeing a white light, presumably. This is quite common, interestingly, in Anime due to the art style almost necessitating that a certain level of "basic prettiness" be included in character designs, such that even the "average" girls or girls perceived as unattractive are at best Hollywood Homely and at worst are average or unattractive in the same way that Rachel Leigh Cook was a "nerd" in She's All That (i.e., she wasn't). For example: Full Metal Panic◊ Where the LEAST attractive girl is still more attractive than most girls in the real world Gunbuster◊ Where even the chubby, nerdy girl is ostensibly sexy enough to cause traffic accidents walking down the street IRL. Mermaid Melody◊ Where, believe it or not, the busty blonde in the tight shirt in the middle was insecure about her breast size. Yes. But this can pop up anywhere, not just Anime. The movie In Time, for example, used the everyone is immortal premise of the film as an excuse to conceive of a world where OLIVIA WILDE (for reference, imagine Lara Croft, but American) is just some faceless nobody in a slum. The women go UP from there. Cleopatra 2525 predicted a future where, on the one hand, mankind is nearly extinct following a cyborg revolution but women are attractive enough that a former model from our time blends in inconspicuously (this is actually the plot, BTW). Baywatch takes place in a world where, apparently, normal women don't exist and have since been replaced by amazonian fitness models-turned-lifeguards. So does Last Action Hero, a plot point referenced by the kid from the movie, who points out there are literally no "average" women in Jack Slater's world--even the cashier at a Blockbuster looks like a Playmate. Another example, outside of Anime but still a cartoon, would be Teen Titans wherein Raven, an insecure introvert who doesn't think she's very pretty, could easily be described as "a buxom, teenaged, gothic fetish doll" and more realistically described as "a Barbie doll that got shipped to Hot Topic by mistake". Anyway, the idea basically is this: It's a world where the basic women we see are not just more attractive than the average (that's expected) but significantly more. While it MAY overlap with World of Buxom, these two things are not one and the same. Theoretically, these characters can be flat as a board, but still implausibly sexy or attractive, and it'd be just as valid--for example, on Sailor Moon, only Jupiter is ostensibly buxom but the show would still count because the most "plain" looking girl on the show is attractive enough to be a model, and the actual pretty girls (i.e., Mars, Venus, Jupiter) would turn heads in the real world so hard they'd cause whiplash.
Hello, Unknown Troper. You'll need to get known to lend a hand here.