Instead, he had three days.

“Those three days were no sleep and just straight sewing,” he said. “I maybe slept about six hours [total].”

Two weeks later, Lamar was strutting around AT&T Stadium in Arlington, Texas, debuting Corrales’s jeans on the third night of the tour. In early May — two shows later — his shorts made their first appearance at Charlotte’s Bank of America Stadium.

Corrales couldn’t have locked in a bigger artist for his first celebrity collaboration. As a hip-hop giant, Lamar is currently one of the biggest figures in the music industry, and his billion-streamed, Grammy Award-winning song “Not Like Us” has further spiked his notoriety in the last 12 months. (The fact that Corrales has been a fan of Lamar since age 12, when he first heard the rapper’s album “good kid, m.A.A.D. city,” is a bonus.)

A portion of Lamar’s onstage garb for his “Grand National” tour matches camouflage pattern with denim: ripped jeans with camo-print fabric peeking through, paired with a camo-print hat, for instance. The aesthetic aligned with Corrales’s knack for fusing denim and “military-esque” designs via CorruptKid. Lamar’s team found Corrales’s signature style on Instagram and asked him to “create it in a new way for Kendrick,” he explains.

Corrales assembled the jeans using Japanese selvedge denim and camouflage-patterned ripstop, a tear-resistant fabric that’s commonly used for military uniforms and outdoor gear. The pants’ massive, layered pockets stretch from the front of each pant leg to the back and provide pops of camo print against the dark denim. Each leg has one large zipper pocket, which is topped with two smaller snap hardware cargo pockets. Corrales’s custom shorts display a similar design, with baggy pant legs that reach the middle of Lamar’s shins.

Fusing the decades-spanning durability of vintage clothes and a military twist on streetwear, the jeans model the ethos of CorruptKid, a name that reflects Corrales’s attraction to “the tension between function and abstraction” in design, as well as the fact that he started the label at 19 years old.

“The meaning is corrupt not in a bad way, but corrupt in the way where I’m taking the norms of fashion and disrupting them a little bit, making them in my way,” he explained.

For Corrales, providing an unexpected element often means tinkering with new shapes and unique placements for buttons and zippers. The garments in his online shop range from items as complex as reversible bomber jackets (one side is denim, the other is flannel) to basic black tees with overlapping and askew breast pockets.

His eye for these kinds of details, as well as his attention to a garment’s durability, runs in the family. Corrales learned how to sew from his grandmother, a seamstress from Costa Rica. Corrales’s family immigrated to the United States when his father was 7 years old; prior to the move, his grandmother made the family’s clothing. She provided Corrales with the foundation of his sewing knowledge, which he supplemented with YouTube videos about skills like pattern drafting.

“My Spanish isn’t the best, and her English wasn’t the best, but we made it work,” he said.

Eager to test out his new knowledge, Corrales quickly became “obsessive” over creating his own designs, often working on garments for 12 to 14 hours a day. (“You don’t sleep, you know?” he said, explaining how he balanced school with his new passion). He established CorruptKid in 2019, and from that point forward, there was no plan B for his career, he said.

Corrales began making new garments and posting them to Instagram on a daily basis, which drew savvy shoppers to his online shop and gradually built his tally of over 35,000 followers. Currently, his biggest customers are from Europe and Japan: “You’re not able to do that without social media,” he said.

Working out of Central Massachusetts has proved to be a stumbling block for networking with other industry professionals, most of whom are in fashion hubs like New York City, but Corrales’s presence on TikTok and Instagram has helped bridge that gap.

“That’s why I think social media is so important for young designers, because it’s like our résumé, our portfolio, and you can reach the entire world,” he said.

Looking ahead, Corrales hopes to organize CorruptKid’s first-ever fashion show and bring pop-up shops to Boston, New York, and potentially Los Angeles. Getting CorruptKid garments into more brick and mortar stores is on the agenda as well, although his clothes are already for sale in stores as far away as Osaka, Japan.

But in the immediate future, Corrales plans to attend Lamar’s “Grand National” tour stop at Gillette Stadium on May 12 with his family, hoping to see the emcee show off his designs in front of over 65,000 people.

“I think it’s just a celebration for the job I did — how far I’ve come in the last five years, and to celebrate that with my parents will be cool,” he said.