In regards to the "father hitting" question, it could of been that the question included both hitting and play hitting. Hitting kids isn't that much of a taboo as in the States. Now...wailing on them is obviously bad but I don't think that's what the question is implying.
It's like maybe Sakurai did something bad as a kid and got a spanking or a small punch yo the forehead. I've see teachers haul the off and throws kids onto the ground, hit them in the forehead, yank them by the collar, kick them, and slap them with the book when they do something stupid or bad here in Japan. Sometimes, it's like "hahaha the teacher is being goofy with the teacher" while other times its like "holy **** that teachwe just pushed the kid out of the classroom."