I think it is tagging example, not naming example.
As written in osm.wiki/Good_practice , a name on the map should be on the ground (e.g. on a signboard or on an official document), and it should be verifiable. But "Word-by-word" translation isn't verifiable.
For example, the English name "Imaizumi-Tatebayashi Line" seems a word-by-word translation of 今泉館林線. And this English name is not verifiable.
In other hand, some other prefectural roads in Gunma prefecture have the English name officially, but following another naming convention. e.g. The prefectural road 前橋長瀞線 is named as "Route Maebashi Nagatoro" in English officially. This English name is verifiable because it is written on a sign. See this image: osm.wiki/File:A_Signboard_which_shows_a_road_name_in_Japanese_and_English.jpg

You have added English namesto many roads and routes (e.g. "Imaizumi-Tatebayashi Line" on the way way/43098500 ), but what is the source of English name?
I think any names are needed sources such as a sign. See also:
- osm.wiki/Good_practice#Map_what.27s_on_the_ground
- osm.wiki/Names#Avoid_transliteration

Please don't break our data!

You have deleted the SECONDARY roads #335726311 and #313944874 by merging into a different TERTIARY road #376538841.
But they are roads in different class and they are unknown from imagery. Then we have lost many informations tagged in these roads, including informations we surveyed.

You can edit geometries of roads from imagery, but don't merge, delete or repleace ways if you don't actually know about there.