Happy Days Season 10 Episode 4 A Night at the Circus ( Air Date 1982-10-26 ) Genre Comedy category. Overview "In an attempt to get Ashley's young daughter, Heather, to warm up to him, Fonzie takes her to the circus. Meanwhile, K. C., Howard's niece, moves in with Howard and Marion while her parents look for a new boarding school. Marion asks Howard to consider letting her stay permanently.".