YOU SAID:
They can never move to Japan.
INTO JAPANESE
彼らは決して日本に移住することはできません。
BACK INTO ENGLISH
They can never emigrate to Japan.
INTO JAPANESE
彼らは日本に移住することはできません。
BACK INTO ENGLISH
They cannot immigrate to Japan.
INTO JAPANESE
彼らは日本に入国できません。
BACK INTO ENGLISH
They cannot enter Japan.
INTO JAPANESE
彼らは日本に入国できません。
BACK INTO ENGLISH
They cannot enter Japan.
That didn't even make that much sense in English.