For professional or cross-platform use, you can access the font through official foundries:
: Specifically crafted to be easy to read for people with low vision or dyslexia. Educational Accuracy
The Ud Digi Kyokasho fonts are proprietary software. They are not freeware in the public domain. Unauthorized distribution on "free font" websites often contains malware or outdated versions. Below are the only legitimate methods to obtain the font.