YOU SAID:

The white mouse the black cat chased was white

INTO JAPANESE

黒猫が追いかけた白ねずみは白かった

BACK INTO ENGLISH

The white mouse that the black cat chased was white.

INTO JAPANESE

黒猫が追いかけた白いねずみは白かった。

BACK INTO ENGLISH

The white mouse that the black cat chased was white.