The purpose of this study is to explore the characteristics of informal relationships in military culture that student veterans experienced after using cell phones. For the purpose of this study, 25 student veterans participated in in-depth interviews. As a result of the study, there was time to perform the first duty assignment and personal time for relaxation. However, the boundary between them was vague, such as erosion of personal time due to the military assignments. After the use of mobile phones, as personal time became more precious (e.g., rest through mobile phones), and as a result, the culture centered on the military assignment and culture centered on the individual coexisted. Informal relationships in the military culture were different from the previous ones. The use of individual cell phone had the effect of alleviating the relationship stress of the soldiers, but also weakened the bonds between the soldiers. This knowledge can be helpful as a reference for military personnel who are willing to develop military retention and success programs.