There is no difference between using a text displaying a 'non Japanese' and a 'Japanese' number.
I suppose there are plenty of fonts using Japanese characters.
If you use a font, that font has to be on the player's device, but that is true for every font.
So, if you are using a 'rare' font, you should use SpriteFonts. Even besides that i read reports everywhere that SpriteFonts perform better on mobile devices.
https://www.scirra.com/tutorials/629/sp ... when-where
To connect them to a coin (graphical wise) , use the pin behavior.
To connect them to a coin (logical, and not using families) ...
Use a container