Even though I can't read japanese,
I can notice that the Mini-Wakuwaku font (as you see in the picture above) is super cute!
This cute font contains two styles: normal and a rounded one, but the difference are just slightly.
It supports Japanese character like hiragana and katakana as well as romaji characters,
numerals, punctuations and more!
Just head to mini-wakuwaku homepage to download the font and also check out the complete character set!
The download button is the button in yellow color.