Child and adolescent digital sexual crime victimization are increasing consistently, on various platforms. Former studies on digital sex crimes targeting teenagers have focused on surveys, legal improvement plans, comparative studies of foreign cases, or victims and offenders themselves. These studies spotlighted the need for improvement of laws via the reality of digital sex crimes against teenagers, and there is a lack of research on platforms used in digital sexual assaults. Therefore, this study aims to examine how teenagers are victimized from the perspective of victim support staff and to find out the problems and possible ways to improve Telegram and Discord, where assault videos are most frequently circulated, shared, and sold. Legislation and research on digital sex crimes, books and reports, statistics and survey data, seminar data organized by women’s organizations, and research literature were analyzed to find out the current status of adolescents’ media usage and damage. After that, through interviews with victim support staff with field experience, teenagers’ experience of digital sex assaults and victim support were analyzed. It was concluded that offenders committed online grooming, by using platforms that teenagers frequently use and can communicate within to approach them in a friendly manner, to exploit, spread and sell victimized videos via the platform. Telegram and Discord are frequently used, and the characteristics of these platforms make it greatly difficult to support the victims. Participants in this study were staff who are providing victim support at investigation agencies, public damage agencies, and educational counseling institutions, and there were various problems and improvement measures according to their fields. Finally, the discussions and limitations of this study, as well as suggestions for future work were presented as a conclusion.