Gwen gets her hair "done," decides she does not like it, and tries to wash it out. But during the process experiences an air raid. As the air raid unfolds, her hair is suddenly back to a "pre" permanent state.
When Hidenari takes Gwen to Japan for the first time, the car transporting them from their ship is a left-hand drive car. The Japanese, like those in the United Kingdom, drive on the left in right-hand-drive vehicles.
When portraying the Doolittle Raid in March, 1942, historical footage was erroneously used showing B-26s instead of film showing B-25s. B-25s have twin rudders while B-26s has single rudders. Most of these aircraft had single rudders making them wrong for the B-25s participating in the Doolittle Raid in March, 1942.
Although the story is set in the 1930's and 1940's, the characters' clothing and hairstyles are those of the late 1950's/early 1960's.