Valkyria Chronicles II

[TheDax]

That's exactly what https://github.com/hrydgard/ppsspp/pull/3922 will do. It makes select toggle upper/lower case, and R button will switch to the next language. It should work for every platform PPSSPP supports.

Edit: As of v0.9.1-1222-g14aa0c6, PPSSPP now supports full-width English characters via the OSK, so have at it. Press L or R until you find "English Full-width".