YOU SAID:

cheers mate, nana sat at the top of the stairs thinking she’s the chaser

INTO JAPANESE

乾杯、ナナは自分がチェイサーだと思って階段の上に座っていた

BACK INTO ENGLISH

Cheers, Nana was sitting on the stairs thinking she was the chaser

INTO JAPANESE

乾杯、ナナは自分がチェイサーだと思って階段に座っていました

BACK INTO ENGLISH

Cheers, Nana was sitting on the stairs thinking she was the chaser