Even though he understands why people jump to conclusions, Gareth Campesinos! still finds it strange that the world expects the members of U.K. indie sensations Los Campesinos! to be permanently peppy.

“We have this outer image of being happy or cute or carefree—those are all words that are often used to describe us,” says the low-key but nonetheless engaging singer, on the line from his mom’s house in Cardiff, Wales. “I think often people think that of us without paying real attention to the lyrics. So when they interview us, they are shocked that we aren’t these seven goons who are always talking about kittens and hugging each other. When we might be a little bit miserable, or we might want to complain about someone or something, people are like ‘My God—you can’t be like that! You’re meant to be happy.’ ”

It’s perfectly understandable why punters and pundits alike get the wrong impression of Los Campesinos!. Much of the Cardiff-spawned septet’s debut, Hold On Now, Youngster…, makes Brooklyn’s famously upbeat Matt and Kim sound more bummed than Morrissey on a diet of Quaaludes and Leonard Cohen. Thanks largely to the all-hands-on-deck choruses and the breathless he-says/she-says interplay between Gareth and covocalist Aleksandra Campesinos!, infectious doesn’t begin to describe the band’s smashingly sloppy mix of golden-era college rock and antifolk-tinted punk.

But sit down with the lyric sheet to Hold On Now, Youngster… and it quickly becomes apparent that Los Campesinos! have more on their minds than throwing a Pitchfork-sanctioned dance party. Anyone who’s ever been in a relationship that’s past its pull date will have no problem relating to “I hate the stench of coffee on your breath/And I hate to feel its warmth against my neck”, this coming at the beginning of the discordant DIY rocker “This Is How You Spell, ‘HAHAHA, We Destroyed the Hopes and Dreams of a Generation of Faux-Romantics’ ”.

Gareth—who, like his bandmates, has embraced the Ramones’ philosophy that everyone in a group needs to have the same last name—is responsible for the band’s lyrics. Nowhere does he do a better job of setting a stage than “Knee Deep at ATP”. A tale of love lost set at the critically adored All Tomorrow’s Parties festival, the song’s best line—“When our eyes meet all that I can read is ‘You’re the B side’ ”—comes when a boy realizes his girl has fallen for another boy, no surprise considering the other guy is wearing a K Records T-shirt.

Gareth’s recollection of Los Campesinos!’s formative period in 2006 is a bit hazy. That’s no surprise, considering the band’s members were ripping it up at Cardiff University, where attending classes ultimately didn’t seem nearly as exciting as majoring in rock ’n’ roll.

“The earliest songs on the record are ones like ‘Death to Los Campesinos!’, ‘Broken Heartbeats [Sound Like Breakbeats]’, and ‘Sweet Dreams, Sweet Cheeks’,” Gareth reveals. “To a certain extent, I can’t even remember what I was on about when I wrote the lyrics to them.”

He’s clear, though, on what started flowing out of him after Los Campesinos! went from a good time on pub night to an Internet-hyped, BBC-blessed sensation. In the tradition of the Hold Steady’s Craig Finn, Gareth has an eye for detail, salting his songs with references to exes who can’t stop talking about The Breakfast Club, ’90s boy-band fashions, and the healing power of Toni Braxton.

Musically, Hold On Now, Youngster… leaves no doubt what bands the various Campesinos! were obsessed with growing up. From the kickoff track “Death to Los Campesinos!” to the album-ending “2007, The Year Punk Broke (My Heart)”, the album is loaded with discordant spawn-of-Superchunk guitars and awesomely off-key vocals. Forget Cardiff University: on “... And We Exhale And Roll Our Eyes in Unison” and “Don’t Tell Me to Do the Math(s)” Los Campesinos! sound like they graduated magna cum laude from Matador College circa ’93. Meanwhile, Death Valley–’69 waves of distortion on “You! Me! Dancing!” suggest a more-than-passing obsession with Sonic Youth during the underground years.

Gareth notes that, for much of this decade, Britain has been overrun with acts determined to become the next Libertines. What separates Los Campesinos! from the hordes of pre-crack–whore Pete Doherty wannabes is a determination to look beyond the British Isles for inspiration.

“When the band came together in 2006, and also leading up to that period when we all wanted to be playing music, the British music scene was primarily dominated by the post-Libertines and post-Strokes bands,” Gareth says. “They were doing something incredibly derivative and not particularly inspiring—it seemed they were only interested in doing something that would get them signed, or make them seem cool. We were more interested in U.S. college rock—your basic bands like Pavement, Dinosaur Jr., Sonic Youth, and Sebadoh. We’re all avid readers of Pitchfork, so that also obviously forms a reference point for what bands that we might listen to. But basically there aren’t a lot of British bands that draw a lot of influences from the U.S.”

And in return, America has embraced Los Campesinos!, with the group now invited to all the major festivals that matter. When he talks about the acceptance that he’s received on these shores, Gareth, tellingly, sounds almost peppy.

“The acceptance in the U.S. is a lot more exciting to us than the acceptance in the U.K.,” he admits. “Not to sound incredibly pretentious, but I think people get us more in America because they know the bands that we’re listening to. The support in the U.K. has come from, like, the NME, which means you get kids who are just following the latest trends and into it because it’s cool to be into it. In the U.S., it seems to be more of a real indie crowd. We played in San Francisco, and there was someone in the front row with a Xiu Xiu T-shirt. That’s the sort of thing that I’m talking about.”

Los Campesinos! play the Plaza Club on Sunday (June 1).