"Frasier Crane", a memorable character on the 1980s bar-room sitcom "Cheers" - was a later addition to the cast, a subplot character who ended up becoming a regular. The idea of a stuffy, would-be New England aristocrat type hanging around a middle class bar was a nice comic foil to a regular set of characters including the bar asshole Cliff and blue collar beer sponge "Norm".
Doctor Frasier Crane was a psychiatrist, an upper class Harvard/Yalie type snob who for some reason had decided to indulge a more proletarian urge to hang out with people other than opera directors and people at MIT. The "fish out of water" trope was a veritable mine, and the stuffy, pretentious Frasier was masterfully portrayed by Kelsey Grammer, more famous for being Sideshow Bob in The Simpsons.
Although spin-off TV was more of a 1970s thing, with Norman Lear finding a one-off character in one show, dragging them into another, and then giving them their own show as a matter of course - the comic potential of an unfettered Frasier was too good to pass up. The character was given its own sitcom, with the millieu transferred to Seattle, Washington, and surrounded by another cast of characters.
In this sitcom, Frasier Crane has moved to Seattle to have a new start, and obtained a job as a radio call-in show host. This enables Frasier to still have the "fish out of water" gag, by having him "slumming" psychiatry by trying to give pithy bon mots on talk radio. To counterbalance this and make it less of a rehash of Cheers, he's very often been paired with his everpresent brother, the fey "Niles Crane", a slight, balding man who is even more quiet, softspoken and Noel Cowardish than Frasier. That gave the writers the opportunity to have Frasier seen more in his "natural" milieu - vying for a spot on the Opera board of directors, finding the latest opportunity to practice his French while ordering at Chez Poussin or whatever five-star in-place is the darling of the upper class that week, and so forth. One memorable moment had Frasier attract the attention of a celebrated opera director, in more ways than one - trying to justify what's obviously a deepening homosexual interest on the part of the other as "just friends" even as the benefits of being in that circle (box seats, the latest in-parties, and so forth) become more and more tempting. The director (played by Patrick Stewart) asks at one point "is there anything Frasier can't do?" and Niles quietly says "we'll find out in about a week."
There was another bit where they come across a shady Russian dealing caviar out of his coat pocket, which turns out to be so good, and so inexpensive they're in essence the Seattle area dealer network for it before long - with them suddenly realizing they've beome jet-set versions of pushers.
But it's one thing to have an upper crust vs Joe Lunchbox dynamic professionally, and another to have it at home.
Frasier's trendy, good zip code apartment is also inhabited by his father, an ex-beat cop who walks with a cane after having been retired from the force after being shot on duty. There's a bit of a sad backstory here, with the blue collar dad trying to interest his two boys in fishing, hunting, camping and football, but both of them turning out to be the polar opposite. He acts as kind of a voice of reason and counterpoint to Frasier and Niles' stratospheric social climbing as well as the great sight gag of having brought a hideous, really hideous torn-up easy chair in 70s green and tobacco hues into his living room.
He brings with him a physical therapist of sorts, a woman named Daphne who speaks with a broad Mancunian accent (scaled back a bit for the benefit of American viewers). For those not in the know it would be the equivalent of having Flo ("kiss mah grits!") from Alice show up to Downton Abbey.
And that's when things get interesting, because Niles becomes completely infatuated with her, and the "will they/won't they" begins.
To be frank, much of the humor in the show came about from Frasier's desperate attempts to find a partner, after his disastrous relationship with good-on-paper but horrible-in-real-life Lilith. Likewise, Niles was in a similar relationship but whereas Frasier dates multiple people over the course of the series, Niles keeps being thwarted in the path to the eventual marriage and relationship that comes about with the blue collar therapist that shows up regularly to help his father.
But really, the whole series was held together by Kelsey Grammer's sesquipedalian ramblings and clownish buffoonery, reacting theatrically to the things normal people take for granted.
One has to wonder just how much of that character is made up, and how much of it is inborn. A few years ago Grammer was tapped to give a speech at some event in Saskatoon. While pontificating and walking, he literally walked off the edge of the stage, injuring his leg in the process.
Sometimes you don't write a character, you find one.