I like to think the bat to the guy's head is intentional but plays off like it's not. The kid's not exactly the confrontational type but he's not gonna let it slide.
Mami definitely isn't 16 which was a woman's legal marige age at the time in Japan. This story definitely doesn't consider him as as exsactly fit partner for someone of her age. This story definitely looks worse in modern times then what 80s Japan would have thought.