Some areas in Asian have no medical facilities and proper mental health care is unavailable. Therefore, online counseling systems are needed. We have been studying and putting into practice online counseling for people assigned overseas. We constructed a system using agile software development for those assigned overseas in Asia. The first step involved developing a prototype system based on system requirements after we repeatedly discussed system development with people in charge of a clinic. Next, we conducted interviews about the online counseling system. We also discussed and analyzed the interviews. Finally, we completed the online Web counseling system by repeatedly discussing possible improvements with the clinic and then incorporating the changes in the system. We report on the construction of the system.