These emojis created by an art student were downloaded by 4 million users in one day. [Photo provided to China Daily]

Those who are passionate about emoji range from professional artists to part-time designers to amateur doodlers, all riding a wave of popularity that has washed over China's social networks and instant messaging platforms for several years. It seems that designing emoji of cartoon images has become a must-do for some cartoonists who want to gain wide public recognition in China.

WeChat's department responsible for emoji says it has the works of 3,000 artists on file, and emoticons are now so commonly used that even the less popular ones can become widely known very quickly.

Wang says his company has about 20 cartoonists, among whom half are college students. All were born in the Internet era, so, Wang says, "they're very sensitive to new things online. They can creatively weave them into their emoticons."

The way in which 12 Buildings' cartoonists work is similar to that practiced in Japan's cartoon industry. The cartoonist designs the image and others help manage it, so they can update stories or bring new series of emojis online very quickly.