HBO is celebrated more for its trailblazing dramas, but many of its half-hour series have also been responsible for pushing the limits of what's acceptable in TV comedy, or even what we consider comedy at all, from "The Larry Sanders Show" to "Sex and the City" and "Curb Your Enthusiasm" to more recent entries like "Girls" and "Enlightened." And what's most striking about HBO's newest comedy, "Looking" (Sunday at 10:30 p.m.) is how non-radical it seems. It's a series about three gay male friends in San Francisco, and incredibly frank about sex (though its explicitness tends to be more verbal than visual), and yet at the moment we're in as a culture, and in the evolutionary history of cable comedy, it just feels like a natural extension of what's come before.

The series opens with its hero, video game designer Patrick (Jonathan Groff), attempting to have anonymous sex at a public park. Where once this would have been presented as an intense, transgressive moment, possibly involving a young man who's been in a closet all his life, here it's just a retro goof from a guy with a thriving social life, and who quickly gets embarrassed and starts looking for any excuse to depart the company of a stranger he'll later describe as "not even hipster hairy, (but) gym teacher hairy." 

The other leads are Agustin (Frankie J. Alvarez), an artist and Patrick's best friend from college, who moves in with his boyfriend and immediately gets the itch to experiment with the nature of, and number of people in, their relationship; and Dom (Murray Bartlett), an aging stud who still lives with his female ex, waiting tables while harboring a dream of opening his own restaurant. If you have trouble learning new character names, "Looking" makes it easy to keep track of the three guys early on by giving them different facial hair: Patrick's clean-shaven, Agustin thickly bearded, and Dom has a trim mustache.

"Looking" was created by Michael Lannan, and most of the early episodes were directed by Andrew Haigh. They do an impressive job of capturing a sense of place and community, both in this small circle of friends and the different parts of the city they frequent. The show looks beautiful and moves confidently through its world.

Arriving nearly 15 years after "Queer as Folk" and so many other cable shows with prominent gay characters (not to mention less bold broadcast network shows), it's incredibly matter-of-fact — if at times amusingly graphic in its descriptions — about its characters' sex lives, tending to focus more on what they want emotionally than physically: whether Agustin really wants to be domesticated, whether Dom might be better off focusing on his career than looking to hook up, and whether Patrick can stop sabotaging himself to have a relationship that lasts long enough to actually call it a relationship.

It's that last aspect that will probably invite the most comparisons to the show that airs immediately before "Looking." This isn't Gay "Girls," but Patrick's tendency to talk his way out of one good situation after another — "Seems like all I do lately is give people the wrong impression," he laments — evokes one of Hannah Horvath's ongoing problems. But his foot-in-mouth disease is, like much of "Looking," played more gently, and on occasion "Looking" plays like a network executive gave Lannan a note that said, "Do it like 'Girls,' only less so."

Through the four episodes I've seen, "Looking" doesn't aim for big, loud laughs. Its humor is more of the sly observational variety, like Patrick skimming OKCupid and complaining, "Instagram filters have ruined everything, and I can't tell if this guy is hot or not," or the way that Patrick lists some of Agustin's recent wild sexual behavior, then tacks on, "And eating meat!" as an additional — and, from the tone of it, biggest — objection.

That said, Patrick is the only one of the three leads to come entirely into focus over these early episodes. Making your location into a character is a great thing — especially coming so soon on the heels of another HBO show that did that so well, "Tremé" — but it helps when the flesh-and-blood characters can stand out from the city they live in. But there's some excellent raw material in here, even if at times I found myself admiring "Looking" more than I was liking it.

Alan Sepinwall may be reached at sepinwall@hitfix.com

NOTE: Due to the crunch of interesting stuff to write about on Sundays, this isn't one I'm going to be covering regularly. Instead, HitFix's Gregory Ellwood will be dipping a toe into the weekly reviewing waters. Look for his take on each episode on his 4 Quadrant blog.