Both girls have an over protective brother. In Yasuko's case, she has one brother who's been taking care of her since their parents died. But in Tao Hua's case, there are FOUR over protective big brothers + one who's bullied by other bros.
Both dramas have these "hooligans" in the school. In Gokusen it's only one class while in Majisuka Gakuen it's the whole school. In Gokusen they're good hearted but misunderstood while in Majisuka Gakuen they just fight for fun to see who's the top of the school.