I avoid Windows, but you might consider this:
• Open Settings (Win + I).
• Go to Time & Language > Language & Region.
• Under Preferred Languages, click the language you’re using (e.g., English) and select Options.
• Scroll down to Keyboards, click Add a keyboard, and choose the Japanese IME or another relevant layout.
• Test switching between layouts using the language bar in the taskbar or by pressing Alt + Shift or Win + Space.