There are multiple accounts of Japanese airplanes over various places in the US. However, US and Japanese documentation agree. The only Japanese plane to fly over the West Coast during WWII was the E14Y1 that flew over Curry County, Oregon in September of 1942 that dropped a total of four bombs. All other accounts of “Japanese” planes turned out to be misidentifications of US airplanes or (in the case of the great LA raid) a bird! Well, there is one other exception. The Zero that was found in the Aleutians in July of 1942 by the Army Air Force and returned to California where it was restored to flying condition, painted with a US Army paint scheme, then test flown. There were no other Japanese aircraft over the West Coast during WWII.
Interesting. A single plan launched from a destroyer or something like that?