I argue that LINE is really suck for multiple device support. LINE won't allow multiple iOS/Android device login (unless using "Lite" app or iPad app only for messaging) and basically the app stores messages and other data on the device. They requires to user to manually backup the data to cloud storage when changing device between same OS. The most pain is that they still don't implement data transfer between iOS/Android so chat log and other data is disappeared. Modern chat apps mush not like this.
