If all of your friends have disappeared, you may have minimized your friends list. Please tap the light gray bar that says Friends (number) on the friends tab to display all your friends again.
If only some of your friends have disappeared, your friend may have deleted their LINE account. When a friend deletes their LINE account, they will be removed from your friends list. To find out about your friend’s usage status, please check with them directly.
Other than the above, please check whether they have been added to the Blocked or Hidden Users list. Please follow the steps below to check your Blocked or Hidden Users list.
1. Tap the settings icon > Friends.
2. Tap Hidden Users or Blocked Users.
Please note that you will not be able to see your friends on the lists above if you have already deleted them. Please add them again.
Let us know if we can make it better.