Popular way for Kobe JET(s) to discuss lesson plans, organize hang-outs, and just communicate in general. Many different LINE groups exist for each neighborhood and ward team.
Note: please refrain from using LINE to contact either of your CIR(s)/Prefectural Advisor(s) about work-related issues, unless an absolute emergency such as a serious injury/illness or home disaster. Work-related LINEs tend to get buried under LINEs from friends and family, and are likely to be forgotten and/or ignored.
LINE is most commonly used on mobile phones, but can also be installed and used on personal computers from http://line.me/download.