Ps and Qs is a reminder to be on one’s best behavior—and it’s the perfect name for a family-owned and –operated menswear boutique on Philadelphia’s South Street, a neighborhood known for its diverse mix of restaurants, bars, tattoo parlours and sex shops.

Brothers and Philly natives Ky and Rick Cao and their friend Jackson Fu opened this discerningly stocked store in 2012, packing the wood-panelled walls with brightly colored apparel from Patagonia, Penfield, Publish and Norse Projects and denim from Nudie Jeans, Naked & Famous, Baldwin and Carhartt WIP. This mixture of street and outdoorsy labels is on display next to tees, caps and cut-and-sew shirts from Ps and Qs’ own locally-made label, as well as sneakers, boots, backpacks and grooming products.

“Ps and Qs is like our personal closet,” said co-founder Ky Cao. “There’s no formula. We buy what we like and what we would wear.”

It’s an attitude that’s served them well. A women’s outpost, Ps and Qs for Her, opened a year ago on nearby Pine Street and its first in-house collection will launch in the fall. Plans are also in motion for a third store that will sell travel goods.

“We don’t want to expand worldwide, we just want to expand in Philly,” Cao said, adding that the in-house label will always be made locally, too.

Ps and Qs isn’t the trio’s first foray into Philly’s retail scene. That was Abakus Takeout, a streetwear and sneaker store that opened in 2008, hidden behind the façade of a Chinatown restaurant, complete with fake ducks hanging from hooks in the window and a faux meat locker for a dressing room. It closed in 2013.

“We made a really fun concept out of it but as we got older our styles changed and we grew out of wearing streetwear,” Cao said. “Now we like more classic styles but we’re from the city so we try to give it a little more attitude. I would say we’re 80 percent classic and 20 percent we dabble in cool stuff.”

Both locations carry everything from crewnecks and casual jackets to headwear and Herschel Supply Co. backpacks. Cao described their customer base as young professionals looking to spend their hard-earned cash on quality goods.

“The women’s market is definitely a lot harder than men’s,” he admitted. “When we guys like one or two stores, those are our stores, that’s where we shop. But for girls, there are so many options out there and they like to see it all.”

Premium denim plays an important role at Ps and Qs, with prices at the men’s store ranging from $98 for Carhartt WIP to $300 for a pair of Baldwin jeans made in the USA from Japanese raw selvedge. At Ps and Qs for Her, prices start at $108 for highwater pants from Carhartt WIP and top out at $275 for Baldwin boyfriend jeans.

“We try to express to the consumer out there that doesn’t know much about denim that it’s a very important piece. It’s not about how many pairs you have, it’s about having the right pairs,” Cao said, noting that each brand they carry offers something different from the next, like 100 percent organic denim from Nudie Jeans or scratch-n-sniff styles from Naked & Famous. “We definitely cover all the bases.”

But it’s the classic styles that sell best in blue-collar Philly: traditional fits in indigo selvedge denim with bronze stitching.

The original Ps and Qs location also plays host to Q&As with artists and brands every quarter, including Aaron Kai, The Hundreds and Naked & Famous, inviting them to stop by the store to talk about how they started.

“At our old store Abacus in Chinatown we used to throw parties and just get drunk and have fun, and as we got older we said these parties are pretty fun but let’s learn before we get drunk,” Cao laughed. “So people sit and listen, ask questions and after we all just hang out and enjoy music and drinks.”

RIVET: What have been some of your bestselling brands in both stores?
Cao: Besides our in-house brand—that’s our bestseller right now—I would say Saturdays NYC, Carhartt, Norse Projects and Publish.

RIVET: What’s your buying philosophy?
Cao: We don’t care about what’s trending. That might be our strongest and our weakest point. We buy what we like and what we would wear. It’s hard to sell stuff you don’t like when you don’t believe in it. And there’s no hierarchy at the store so we all buy together. We vote on what product we’ll carry and if one person doesn’t like it then we won’t do it.

RIVET: Any key colors for spring?
Cao: We love colors so we have a lot of choices. We don’t sell too much black but you name it, we probably offer it in color, like a yellow jacket or a pink long-sleeved tee.

RIVET: Any trends you’re sick of seeing?
Cao: “Vintage” rock ‘n’ roll T-shirts. At least learn about the band before you wear their T-shirt.

RIVET: What’s your favorite part of your job?
Cao: That I get to do it every day. It’s the greatest thing in the whole world. I can’t even call it work. What’s great is that I get to be myself, do what I want and recreate it every day.