For some reason, if you install MacOS 12 (Monterey) on a 17-in MacBook Pro 2011 Model using OpenCore Legacy Patcher and install the AMD GPU Patch, you will lose the ability to use the Japanese Hiragana IME.
For most people that type Japanese, we use the hiragana input method, so this poses a problem.
The solution .. install the Google Japanese IME.
Once this is installed, you will have the HIragana IME restored.
後で、日本語を書ける。。。