Normally for this sort of thing it is noted down in the release lists for games. You can then sort by Japanese region but include things with more than Japanese language in. Any posts on a thread like this then tending to be if a game includes English text but needs a cheat/hack to access (don't know for the 3ds but seen plenty of times on the GBA and DS) or if it is playable without any Japanese knowledge/minimal Japanese knowledge (most menus in most games are kana after all) with puzzle games and such usually being good candidates here.
Sadly I don't have a suitable website to link you --
http://www.advanscene.com/ will happily do GBA, DS and PSP for this but its 3ds list is not available in its advanced search.
http://3dsdb.com/ has a list of games including region and languages contained but its search functionality is limited. You can download the XML database though and probably import that into something. I managed to get it working in libreoffice calc (click data- XML source, imported everything into a new page, and then did a sort (data menu-sort) by region and then language)
In which case it spat out.
1513 |
Club Nintendo Picross
|
Nintendo
|
JPN
|
en,fr
|
Kirin
|
865 |
Bravely Default: For the Sequel
|
Square Enix
|
JPN
|
en,fr,de,it,es,ja
|
HR
|
547 |
Pokemon X
|
Nintendo
|
JPN
|
en,fr,de,it,es,ja,ko
|
Kirin
|
548 |
Pokemon Y
|
Nintendo
|
JPN
|
en,fr,de,it,es,ja,ko
|
Kirin
|
1324 |
Pocket Monsters Alpha Sapphire
|
Nintendo
|
JPN
|
en,fr,de,it,es,ja,ko
|
Caravan
|
1325 |
Pocket Monsters Omega Ruby
|
Nintendo
|
JPN
|
en,fr,de,it,es,ja,ko
|
Caravan
|
2250 |
Pocket Monsters Sun
|
Nintendo
|
JPN
|
en,fr,de,it,es,ja,zh,ko
|
HR
|
2251 |
Pocket Monsters Moon
|
Nintendo
|
JPN
|
en,fr,de,it,es,ja,zh,ko
|
HR
|
2439 |
Pocket Monsters Ultra Moon
|
Nintendo
|
JPN
|
en,fr,de,it,es,ja,zh,ko
|
HR
|
2440 |
Pocket Monsters Ultra Sun
|
Nintendo
|
JPN
|
en,fr,de,it,es,ja,zh,ko
|
HR
|
886 |
Gyakuten Saiban 123: Naruhodo Selection
|
Capcom
|
JPN
|
en,ja
|
HR
|
1109 |
Thomas to Asonde Oboeru Kotobato Kazu to ABC
|
Nippon Columbia
|
JPN
|
en,ja
|
HR
|
1121 |
F-Zero
|
Nintendo
|
JPN
|
fr
|
BigBlueBox
|
and might as well do Korea
2162 |
Pokemon X
|
Nintendo
|
KOR
|
en,fr,de,it,es,ja,ko
|
BigBlueBox
|
2163 |
Pokemon Y
|
Nintendo
|
KOR
|
en,fr,de,it,es,ja,ko
|
BigBlueBox
|
2164 |
Pokemon Omega Ruby
|
Nintendo
|
KOR
|
en,fr,de,it,es,ja,ko
|
BigBlueBox
|
2165 |
Pokemon Alpha Sapphire
|
Nintendo
|
KOR
|
en,fr,de,it,es,ja,ko
|
BigBlueBox
|
As far as games that work with hacks and games that you don't need any real knowledge of the language to play you are on your own/waiting for someone else. I don't think you will have any problems with later releases but it is a thing some experience where later versions of a game lost or gained something (3ds doing updates instead means that is kind of minimal).