[3] Jo Seok graduated from Jeonju University with a major in video cultural studies in 2002, and wanted to infuse an interest in cartoons to those who haven't been fans of graphic novels.

[5] When Jo got married in 2014, he did not have a wedding ceremony or honeymoon trip because he did not want a lapse in his update schedule.

[5] On 7 November 2016, airline carrier Air Seoul announced that it had collaborated with Naver Webtoon to produce pre-flight safety video.

[7] On September 20, 2018, the first animated short series based on The Sound of Heart was released on Naver WEBTOON YouTube Channel.

[8] Netflix ran another series titled The Sound of Your Heart - Reboot, produced by Kross Pictures.