A sequel to one of China’s biggest box office hits, the wry romantic comedy “Fei Cheng Wu Rao 2” (“If You Are the One 2”) — the first Chinese release to open in its homeland and North America on the same day — continues the odd-couple courtship saga of wealthy, middle-aged retiree Qin Fen (Ge You) and serious-minded young air hostess Xiaoxiao (Shu Qi).After an amusing prelude in which Qin presides over a lavish divorce ceremony for an amicably splitting married couple, he and Xiaoxiao decide to address their own relationship barriers — her youth and beauty, his cynical, childish sense of humor — by entering into a trial marriage while on a trip to the country’s tropical southeast.