Hi Chandramouli_2014,
Good day! This is Jhakesong an Independent Advisor and I will be happy to assist you with this.
A lot of people are suggesting to get that option added into Windows 10 in the future updates. So far no news for it yet. I also tried to look for Third party alternatives but there aren't any.
The option is to still type using an English keyboard and get them out in Hiragana, Katakana and Kanji. You just need to install the MS-IME to be able to type in Japanese. Here's how:
https://www.coscom.co.jp/learnjapanese801/msime...
I also suggest sending a feedback via Feedback Hub so the developers can take notice that a lot of people really need this feature on windows 10. Just press Windows key + F to launch feedback hub from your computer.
Let me know how it goes. Have a great day!
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