Yumi Katsura could be the greatest fashion designer you’ve never heard of. One of the world’s bestselling luxury wedding-dress designers, as well as a celebrated couturier, she was venerated in her native Japan as a cultural icon and an inspirational business leader. Among her most celebrated pieces are a paper ‘washi mode’ dress housed in the Metropolitan Museum of Art, a vestment worn by Pope John Paul II and a diamond-laden wedding gown ranked among the most expensive of a...