YOU SAID:
since when did you care about me?
INTO JAPANESE
いつから気になったの?
BACK INTO ENGLISH
Since when did you become interested?
INTO JAPANESE
いつから興味を持ちましたか?
BACK INTO ENGLISH
When did you become interested?
INTO JAPANESE
興味を持ったのはいつですか?
BACK INTO ENGLISH
When did you become interested?
You should move to Japan!