Everything is fair in the war. What went wrong when Japan attacked Pearl Harbor?

There is nothing wrong with Japan's plan to attack Pearl Harbor. The plan is perfect, but it's just bad luck. The US capital ship only temporarily left Hong Kong, which eventually failed to be completed as planned, but it still caused heavy losses to the US Navy.

Aside from the specific plan, on the whole, Japan underestimated the strong industrial base of the United States, which is why Isoroku Yamamoto initially opposed this plan.