YOU SAID:
Let's go to a slumber party
INTO JAPANESE
パジャマパーティーに行きましょう
BACK INTO ENGLISH
Let's go to the pajama party
INTO JAPANESE
パジャマパーティーに行こう
BACK INTO ENGLISH
Let's go to the pajamas
INTO JAPANESE
パジャマに行こう
BACK INTO ENGLISH
Let's go to pajamas
INTO JAPANESE
パジャマに行こう
BACK INTO ENGLISH
Let's go to pajamas
That didn't even make that much sense in English.