Comic books are known for unlikely pairings — from the classic meeting of Superman and Spider-Man to the more recent face-off between Archie Andrews and the movie alien Predator.

But what could unite the comics legend Stan Lee and the YouTube personality and makeup expert Michelle Phan?

The answer is Line Webtoon, a portal for free digital comics that was founded in South Korea and is now making a big push into the United States. The site will announce partnerships with Mr. Lee, Ms. Phan and others at the Comic-Con International event in San Diego this week.

“In Asia, comics and manga and anime are definitely ingrained in the broader pop culture,” said Tom Akel, the head of content at Line Webtoon. “It’s almost difficult to put into words the scale and success of Webtoon over there.”