SEOUL, South Korea -- The blaring roar of cars, brisk footsteps of office workers, and the vibrant voices of children echo through a dim grocery store parking lot. It's four in the morning, and most of the city is sound asleep. But this corner of Seoul is buzzing with excitement as people try to get their hands on the most-wanted treat in South Korea's capital at the moment: Pokémon bread
Dozens of people are standing in line in front of the store's entrance. Some spread out newspaper and cardboard boxes on the floor to rest their legs after hours of waiting for the store to open. Competition is fierce; there are only 100 packages in stock each day.
A new consumption craze has ignited in South Korea. Day and night, Korean millennials and Gen Z members race to local markets, chase delivery trucks, and join hour-long lines for Pokémon bread -- only to run into sold-out signs plastered on walls and windows.
"I visited over ten convenience stores looking for Pokémon bread," 13-year-old Joon-su Kim, who said he woke up at 4 a.m. to line up at the grocery store, told ABC News.
Pokémon bread is a $1.20 snack wrapped in Pokémon packaging that comes with cute character stickers. The brand offers seven types of pastries to choose from, including creamy cheesecake and rich chocolate cake. The Pokémon sticker in the package is random and adds a pleasant surprise to the experience.
The cake first came to Seoul's snack stands in 1998 and was popular among teenagers who bought the bread to complete their sticker collection. The production came to a halt in 2006 due to license issues.
The bread made a glorious comeback Feb. 24 this year and achieved a record -- selling over 8.4 million packages in less than 40 days.
"I have fond memories of collecting Pokémon bread stickers when I was in elementary school. I was thrilled to hear that they were producing it again and decided to wait in line this morning to try it out," 35-year-old Min-soo Park told ABC News.
Apart from the nostalgia for millennials, the enthusiasm spilled over to a larger group of consumers -- from elementary school to college students -- after the bread took over the Internet.
Avid Korean millennials are posting photos of their Pokémon sticker collections online, spurring a viral social media challenge to acquire all 159 stickers. Some are trading stickers and even pay up to 60 times the original value for rarer ones.
"Many of my friends wanted to know how I was able to buy Pokémon bread after I posted a picture of it on Instagram. It's really hard to find," 22-year-old Son Yeeun told ABC News.
Even top K-pop stars, such as BTS's Jin and Girl's Day's Mina, have joined the challenge.
"Pokémon bread enjoys its explosive popularity because it evokes nostalgia and rejuvenates millennials," Professor Lee Eun Hee from the Department of Consumer Science at Inha University told ABC News. "It's also a social media meme that brings various generations together."