YOU SAID:
A coin got coined into a coin thing
INTO JAPANESE
コインがコインで硬貨になってしまいました
BACK INTO ENGLISH
The coin has turned into a coin.
INTO JAPANESE
コインはコインに変わりました。
BACK INTO ENGLISH
The coin has been turned into a coin.
INTO JAPANESE
コインはコインに変わりました。
BACK INTO ENGLISH
The coin has been turned into a coin.
That didn't even make that much sense in English.