Mom and Dad decide to divorce and their kids try to bring them back together — it's a familiar story here, on screens big and small. And it's not hard to understand why: The kids nearly always succeed, making for a happy ending. Veteran hitmaker Yoji Yamada uses it for his first comedy in two decades, the upcoming "What a Wonderful Family!" ("Kazoku wa Tsuraiyo") and his choice is sound — in terms of the box office, anyway.