The Japanese plan was:

The Japanese used the codename "Operation Hawaii" for the attack. This later changed to "Operation Z."

Admiral Yamamoto had initiated the attack against the U.S. Pacific Fleet.

If they do that, the Americans would not be able to fight back

Prelude

On November 26 a Japanese fleet with 360 planes sailed to a point 440 km north of Hawaii.

Almost the entire Pacific Fleet was tied around Ford Island in the harbor

The naval facilities at Pearl Harbor were almost undefended.

The naval base was not on a state on high alert.

Attack

A minimal number of soldiers was on duty at the time.

By the time the attack was over, every battleship in Pearl Harbor had sustained significant damage.

45 minutes later, the other group flew over the water around the island

One U.S. Army officer noticed large flight of planes on his radar . He was told to ignore them. Japanese bombers were mistaken for an incoming group of American planes which was expected at that time.

One group proceeded overland at low altitude across the island just before 8 a.m.

Epilogue

Sudden attack resulted in a enormous influx of volunteers into the U.S. armed forces.

The day after the assault, America declared war on Japan

the Navy and Army commanders on Oahu, were relieved of duty

The assault had left intact the base’s most vital onshore facilities–oil storage depots, repair shops, shipyards and submarine docks

The Japanese lost from 29 to 60 planes, five small submarines, two fleet submarines, and fewer than 100 men.

More than 2,000 Americans soldiers and sailors died in the attack, and another 1,000 were wounded.

The Japanese destroyed nearly 20 American naval vessels, and more than 300 airplanes.

Interesting facts

The Pearl Harbor attack has been depicted in many films: Pearl Harbor in 2001, From Here to Eternity in 1953, and the Tora! Tora! Tora! in 1970.

American cryptanalysts had been ordered to concentrate on Japanese diplomatic traffic, rather than military messages. If it was the other way around - disaster of Pearl Harbor might have been prevented.

Japanese Commander called out "Tora! Tora! Tora!" ("Tiger! Tiger! Tiger!") while flying over Pearl Harbor. It was a message to the Japanese navy telling them they had surprised Americans.

U.S. staff were still in pajamas and eating breakfast when the attack began.

“Remember Pearl Harbor!" - a rallying cry for the U.S. during World War II .

The significant innovation by the Japanese Navy was the use of air-launched torpedoes against the ships.

The U.S. Navy had dismissed its importance to Pearl Harbor because previous harbor was around 23-meters deep, almost double the depth of Pearl Harbor. It was not believed by Americans that air launched torpedoes would work in shallow waters.