Before my Seoul sojourn, I asked Yang Hu, an analyst at the data analytics company Euromonitor International, about Olive Young's rise.

Yang said Korean stores that only sell one brand have struggled in recent years, especially as e-commerce has exploded.

At the same time, social media channels allowed a slew of new brands to enter the market, Yang said, and customers were spoiled for choice.

"Olive Young gained traction as a 'one-stop' destination where shoppers could discover and experience a wide range of brands," Yang told me. "By quickly onboarding trendy K-beauty labels across both online and offline channels, Olive Young successfully attracted consumers eager to explore new offerings."

With that in mind, and a loose to-buy list in hand, it was time to shop.

Every Olive Young outlet I went to had digital displays featuring K-pop boyband members, like Felix Lee of Stray Kids, an LVMH muse, and Seventeen member Jeonghan, the face of makeup brand Banila.

It made Sephora's posters of Western celebrities look low-key and understated. As an avid appreciator of K-pop men, I was not complaining. The displays enticed me to pick up a cream blush from Banila, which I did not need.

There's a reason displays at Olive Young are so K-pop-centric.

"K-pop and celebrity influence have played a pivotal role in the global expansion of K-beauty," Euromonitor's Yang told me.

Yang added that another key driver for the beauty industry lies in the country's advanced equipment and design manufacturing infrastructure, which has helped local beauty brands produce high-quality formulas at an accessible price point.

Olive Young Seongsu featured a curated zone of makeup products, where an entire cart was dedicated to fuss-free makeup looks for "workaholics."

This cart felt like it catered specifically to millennial women like me, who would shell out for makeup to make us look and feel more alive.

I was visiting outlets in some of the city's more touristy areas, so it was unsurprising that signs about top sellers were in English. Piles of these products, stacked high, were placed prominently near the store's entrance in Myeongdong.

According to Euromonitor's statistics, a few brands consistently notch top sales at Olive Young: Mediheal, Roundlab, Torriden, Aestura, and Innisfree.

I have more Rom&nd lip tints than one woman could need.

I collected half a dozen lip tints from the brand while shopping in Tokyo in November, including some Japan-exclusive colors. I couldn't resist picking up four lip tints from the "Juicy Lasting Tint" range, a top-ranking product at the chain.

Each went for 9,900 South Korean won, or around $7.

Then it was on to the skincare.

Before taking the plunge at Olive Young, I spoke to Erica Choi, an esthetician and cofounder of the New York-based beauty brand Superegg, and asked her for some of her top Korean skincare recommendations.

The Cell-Fusion C sunscreen, which sold for around $19 for a pack of two, was a great buy.

"This is a cooling, weightless sunscreen that offers SPF protection without greasiness — perfect for humid weather or active days outdoors," Choi said.

Choi's tips for use: "Apply generously as the final step in your morning skincare routine. Reapply every two hours when outdoors. Let it fully absorb before makeup to prevent pilling."

I take my sunscreen very seriously. This Round Lab tinted sunscreen was one of the top products promoted by TikTok influencers.

I snagged a tube for around $12, and it's become a core part of my routine.

Choi recommended this balm-to-foam cleanser, which she said would simplify my facial cleansing routine.

"The balm texture melts away sunscreen, makeup, and excess sebum, then transforms into a soft foam when water is introduced," Choi said.

Choi's tips for use: "Scoop onto dry skin and massage to dissolve buildup. Add water to emulsify into a light foam, then rinse. For deeper cleansing, use a dual-textured pore brush around the T-zone or jawline."

The Booster Pro from Medicube has fans like Kylie Jenner. Influencers on TikTok and YouTube say that running the gadget over their skin helps liquid skincare products absorb more effectively.

It seems like the brand is cashing in on cute with this Sanrio collaboration. I didn't pick it up because I was close to busting my budget, but three women who were browsing at the same shelf grabbed one each.

The Sanrio collab version of the Booster Pro was selling for around $250.

Most of my purchases at Olive Young came from the sheet mask shelves. I was already a fan of the Mediheal Madecassoside sheet masks, so getting them with tax-free shopping was an absolute steal.

I spent around $150 on various sheet masks, including cooling and gel masks — about $2 per mask.

My TikTok scans surfaced the $18 Needly toner pads as must-buy items from Olive Young. Choi, the beauty expert, also recommended this.

"These pre-soaked toner pads are designed for gentle daily exfoliation and hydration," Choi told me. "They're great for those with clogged pores, mild breakouts, or textural dullness."

Choi's tips for use: "After cleansing, use the textured side to exfoliate, then flip to tone. Gently pat in any remaining essence. It can double as a quick mask by placing pads on targeted areas for a few minutes."

This one wasn't on Choi's list, but TikTok videos showcased Mediheal's multicolored toner pads. They come in 200-sheet combo packs and cost around $20 per pack.

I rotate between three variants, depending on the day.

In all, I left Olive Young around $400 poorer.

While I didn't spend all my money at the chain, I did have 12 extra pounds of luggage to bring home — and a dozen new K-beauty products to try out.