CASE sentence for SQL query I have a question abut MySQL

I would like to handle a column with characters without changing the original DB. Below is the levels of the column named 'Maker'.

기아, 현대, BMW, VolksWagen, Porsche
So there are about 10 기아s, 20 현대s, 30 BMWs and so on.

As you can see, some of them are written in Korean and others are in English.
I do not want to touch English-written words. I only want to change Korean words into English.

I tried to you CASE and IF sentences like below.

SELECT
    CASE
        WHEN Maker='기아' THEN 'KIA' 
        WHEN Maker='현대' THEN 'HyunDai'
    END AS new_Maker
FROM table_name


It successfully changes KIA and HyunDai but BMW, VolksWagen, and Porsche shows as NULL.
I would appreciate any advice. Thank you.
You haven't specified what happens for values other than '기아' ('KIA') and '현대' ('HyunDai').
Try

SELECT
CASE
    WHEN Maker='기아' THEN 'KIA' 
    WHEN Maker='현대' THEN 'HyunDai'
    ELSE Maker
END AS new_Maker


FROM table_name