I'm not at all against rooting the phone... but if you don't want to, you can download the Motoya fonts to many Android phones without rooting.
On my Samsung Galaxy tablet, when you go to Settings, Display Settings, Font Style, there is a list of pre-installed fonts that you can use for your system font. There is also a box down the bottom that says "Get Fonts Online". You could, no doubt, check for this in the shop before you buy, even if you buy elsewhere. I only have experience with my phone, but I expect that the presence of this option indicates that the phone is compatible with the app called " fontomiser or galaxy fonts"
https://market.android.com/details?id=co...ntomizerSP
See also, this thread
http://forum.koohii.com/showthread.php?tid=8911&page=1
In addition check Option, Applications... There should then be an option at the top to tick, to allow Unknown sources, ie non-market apps. Most phones seem to have this, but not all. Looking at the feedback the guy has received for his app, if you dig deep enough you will see some comments about success with non Samsung phones, but checking your menus, as above, to see if you have what the writer of the app called 'flipfont library', may well be your best best.
As mentioned by others, if you want to choose any font, including Japanese, in Ankidroid, you don't need any of this. But once you have changed your system font it will, of course, work with all apps Including English language ones. And it is very quick to switch back/switch between different system fonts, once they are installed.
Good luck