Disclaimer: Not a console per se but there are threads in this section about games for PCs and there are quite a few emulators available for Raspberry Pi now. There are some pretty neat DIY UMPCs being made with RPis as well so the concept would seem to fit fairly well with this community...
Here is Tagaini Jisho, a software to help learning Japanese.
This is a simple vanilla build of the software, using Qt5
History log
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Build 02
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Embedding hanazono font to avoid missing glyphs
Build 01
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Initial build