Alice-Miranda in Japan (Book 9) by Jacqueline Harvey
When Alice-Miranda, Millie and Jacinta travel to Japan during the school holidays, they are in for a fascinating treat. Dolly Oliver, the family cook, has been invited to speak at a conference in Tokyo on her Just Add Water (JAW) food creation. But she is even more interested in her newest invention, and vows to try it out while overseas.
Alice-Miranda becomes embroiled in an elaborate missing persons hunt when a gift from her father confuses the authorities. Things come to a head when Alice-Miranda and her friends are invited to dinner at the Imperial Palace in Tokyo, and the plans of a jealous sister begin to unravel, with startling consequences.