YOU SAID:

Box is my best friend.

INTO JAPANESE

ボックスは私の親友です。

BACK INTO ENGLISH

The box is my best friend.

INTO JAPANESE

この箱は私の親友です。

BACK INTO ENGLISH

This box is my best friend.

INTO JAPANESE

このボックスは私の親友です。

BACK INTO ENGLISH

This box is my best friend.