Music and mochi make a powerful combo.  More than 10 years ago — when bookwriter Lainie Sakakura and composer/lyricist Paul Fujimoto first began adapting Jamie Ford’s bestselling 2009 novel “Hotel on the Corner of Bitter and Sweet” into a musical — a song about mochi not only kick-started their collaboration; it helped convince Ford that his beloved book should take on this new form.  “I was a little skeptical,” Ford said of the cold call he got from the writing team, along with a couple of sample songs. “Not of Paul and Lainie’s intentions, but just that they would get the book, you know? But they sent me demo songs they’d recorded with some Broadway kids, and I ugly cried all over my keyboard; it was so good.”  Now, this team is bringing the musical to Seattle, a hometown shared by Ford, Fujimoto and the foundational text itself.…