YOU SAID:

Cats cant be extremely happy without first being sassy

INTO JAPANESE

猫は最初に生意気でなくてはならない

BACK INTO ENGLISH

Cats must be cheeky first

INTO JAPANESE

猫は最初は生意気でなければなりません

BACK INTO ENGLISH

Cat must be cheeky at first

INTO JAPANESE

猫は最初は生意気である必要があります

BACK INTO ENGLISH

Cat must be cheeky at first