I wanted to use Colemak while typing Japanese (because my hands no longer type in QWERTY well) but tutorials on how to set this up was hard to find, and I remember seeing some sort of Windows registry hack but I can't find any specific instructions, so instead, I opened Google Japanese Input and I set the romaji table to the equivalent Colemak keys.
Since it took a long time to do, and it'd be really bothersome if you'd have to do it yourself, I'll upload the configuration file. Just open Google Japanese Input's "Properties" (プロパティ), choose "Edit Romaji Table" (ローマ字テーブル → 編集…) click "Edit" (編集…) again, then "Import" (インポート), then choose the file that you can get from this link:
https://drive.google.com/file/d/1fSu5zj … sp=sharing
Hope I was able to help someone :)
-- Kyle