Constant IME Input Method setting for a Windows Form

Question

Hi,

I have a simple c# windows form with a textbox and button that, when clicked, displays a simple MessageBox.

 

With the cursor in the textbox, I can select the Japanese language and desired Input Mode (Hiragana, Full-Width Katakana, etc) from the IME toolbar.

 

 

However, when the click on the button to display the MessageBox then return to the text, the Input Mode on the IME switches to "Direct Input", regardless of what it was originally set to. The IME language remains Japanese, but the Input Mode changes.

 

Is there a way to keep the IME settings contant while in a windows form even if you bring up message boxes, minimize, etc?

 

Thanks.