Moobin's sister Moon Sua is also a K-pop singer, part of the girl group Billlie. The siblings had previously spoken in public interviews about their dependence on each other.
South Korea has the highest rate of youth suicide among developed countries, at about 26 per 100,000 people. While its overall suicide rate is falling, deaths of those in their 20s are rising. Several young South Korean celebrities have died in recent years - with some of these cases acknowledged as suicide.