Recently I gave up Windows 10 and WSL2 for a full, dedicated Ubuntu install.

When I was setting up my Japanese IME, I fired up Visual Studio Code as a scratch pad to type and test a bit and quickly noticed that it was not accepting Japanese input properly.

The icon in the system tray indicated that I was in Japanese mode set to Hiragana input, but only ASCII characters were appearing in my open editor.

After some searching, I discovered several posts alluding to the issue, only mentioning Korean, but I suspected the issue was likely the same.

The solution is to remove the version of VS Code that Microsoft provides a Snap install for. Instead, download their official .deb archive from https://code.visualstudio.com/ and install it using apt package manager.