Watch Whose Baby Is in the Classroom? (1970) Official Trailer

This movie stars Peter Chen Ho as a male teacher in an all girls school. The girls are teens and, since they live there, are kind of tickled to see a male teacher. They don't particularly lust after him, but they kind of crush on him. The title of the film refers to a baby that Chen minded as a favor in a doctor's office, only to find the mother left him with Chen. Chen has to take care of the baby and, inevitably, has to bring him to school and hide him, as he lives there also.