Line while shown as experimental installs and works - haven't tested calls. There are two catches:
First if you don't have Asian fonts you will only see squares. The way I solved this I copied all fonts from existing Win10+Office install (with added Japanese input) to Windows/Fonts. After that Line properly shows Asian characters. I would suggest for installer script to download and install Asian fonts. I tried manually installing Mincho and Gothic but only those two were not enough, so I pulled all fonts from Windows installation
The 2nd problem is input. I can use fcitx to input kana and kanji but until I press enter, I don't see what is being entered. Maybe a workaround can be found.
The 3d minor annoyance is that if you alt tab from line, there is a black border drawn where Line window was, it goes away if you minimize Line Window.