It's the first day at Robert F. Kennedy Junior High for Kevin Arnold and his best friend, Paul Pfeiffer. Brian, Winnie's brother, is killed in Vietnam and Kevin and Winnie share their first kiss.
At Brian's funeral, all Kevin can think about is Winnie and their kiss. At school, sex education leaves a lot to be desired, so Paul and Kevin steal a copy of Everthing You Always Wanted To Know About Sex from a bookstore.
Kevin gets a glimpse into his father's life after spending the day with him at his office.
Karen brings home a new boyfriend, Louis, who Kevin immediately dislikes.
Paul tries to find out if Lisa Berlini likes Kevin or not, leading him to find the courage to call her on the telephone.
Songs: The Monkees
-- I'm a Believer, Nino Rota -- Theme from Romeo and Juliet
Note passing leads Kevin to ask Lisa to the school dance, but things change quickly after she accepts a date with another guy.