Now You're One of Us by Asa Nonami

In the tradition of Daphne du Maurier's Rebecca and Ira Levin's Rosemary's Baby, here is a new classic about the bride who's no longer sure what to think. All families have their own rituals, secrets, and credos, like a miniature religious cult; these quirks may elicit the mirth or mild alarm of guests, but the matter is rather more serious if you're marrying into a household. If its's a Japanese one with a history, the brace yourself: some surprising truths lurk around the corner.