Yes. But keep in mind that Webtoon has its own rules and policies regarding manga submissions. You'll need to make sure your manga aligns with them to get published successfully.
A movie's box office earnings of one billion was a rather high figure. The box office referred to the movie's current ticket sales and revenue, and a billion box office meant that the movie had already sold a billion movie tickets. Although the exact box office figures might vary depending on the movie's release time and audience, a billion yuan box office was usually considered a sign of a movie's great success.
The opening billion was a free novel that could be read online. The specific reading method and platform might need to be further searched, but according to the information in the search results, it could be confirmed that the opening one billion cash could be exempted from reading.
Webtoon does have a few 18+ comics. However, their availability can vary depending on your region and the platform's content regulations. Some might be hidden behind age verification or specific access settings.
The 'Do It One More Time' manhwa webtoon is appealing because it combines an interesting storyline with beautiful illustrations. The character development is well done, and it offers a fresh take on common themes.