Seoul's Hanbok-Knot Cap Hit 2.7 Million Views in Japan With Zero Ads

A single photo posted by a Japanese user on X on the 7th did more for Seoul's city merchandise program than any campaign could have planned. The image showed someone wearing the Seoul My Soul Belt Cap, a cap that grafts traditional hanbok cord-knot detailing onto a clean modern silhouette, and it collected 2.7 million views, 32,000 likes, 7,900 reposts, and 9,300 bookmarks before Seoul City had said a word about it publicly.

The cap launched on the 3rd as a collaboration between Seoul's city brand SEOUL MY SOUL and traditional knot-craft fashion label ONGO. It is the kind of product that tends to get talked about in design circles without crossing over to a mass audience, which makes the organic Japan reach worth paying attention to.

What the sales data actually shows

Seoul City published its first-ever foreign-buyer merchandise top-10 on the 23rd, drawing on purchase data from both online and offline channels throughout the year. The core buying demographic was people in their 20s and 30s, and preferences split noticeably by channel.

In physical stores, small-format souvenirs tied to Seoul's landmarks dominated. The combined online and offline bestseller at the DDP Design Store was a 50-piece Seoul sticker collection, followed by postcard sets featuring Seoul's four great gates and four palaces, a Kongkongi postcard series, and Namsan and Gwanghwamun magnets. Most of the top sellers were priced under 10,000 won.

Higher price points held their own when the Korean design identity was clear enough. A Durumagi rain coat, made in collaboration with a small independent producer and priced at 99,000 won, sold through its entire stock. At the Seoul Gallery branch inside Seoul City Hall, which opened in February and draws a foreign visitor share above 22%, a mother-of-pearl wind-chime box at 59,000 won has been selling steadily.

At Seoul My Soul retail locations across Jongno, Myeongdong, Gwanghwamun, Gangnam Station, and Yeouido Hangang Park, the consistent performers were items in the 10,000-won range: Haechi random figures, magnets, and ballpoint pens featuring Seoul's guardian-spirit mascot. Online, character merchandise pulled stronger, with Haechi playing cards, a white-tiger plush keyring, and a Haechi & Soul Friends wooden block tower among the leaders.

The brand behind the label

SEOUL MY SOUL launched publicly in August 2023 after the city began developing it in 2022. The concept borrows from city-brand precedents like New York's I♥NY, using the city name as a unified identity mark. The Korean phrase embedded in the brand's philosophy translates roughly as "when hearts gather, Seoul is made," with a heart, an exclamation mark, and a smile representing the city's spirit, experiences, and sense of fun.

The city is broadening its private-sector collaborations, with a Seoul stamp custom T-shirt made with Musinsa Standard, a Joseon royal court refreshment gift set from Jung Kwan Jang, and a Seoul snack rice chip all in the current lineup.

Kim Hyeong-rae, Seoul City's public communications director, said the belt cap's Japan moment and the foreign-buyer data together confirm that "Seoul-like design is being consumed as competitive content." The city plans to keep expanding merchandise that carries Seoul's culture and stories, he added. Whether the belt cap's viral run translates into sustained international retail interest is the real test, but the unprompted 2.7 million views suggest the design was specific enough to earn its own audience.