From:
PEARL HARBOR OPERATIONS: General Outline of Orders and Plans Prepared by Military History Section Headquarters, Army Forces Far East

Navy Directive No. 1
5 November 1941
Directive to: Yamamoto, C in C, Combined Fleet

1. The Combined Fleet will advance necessary forces at a suitable time to their preparatory points to stand by for the start of operations in the event of unavoidable hostilities against America, Great Britain and the Netherlands, in the first ten days of December.
2. During the above-mentioned advance, strict watch will be kept against unexpected attacks.
3. The operational policy against America, Great Britain, and the Netherlands, in case of hostilities, is scheduled as cited in the separate volume.

Chief of the Naval General Staff
Nagano, Osami

Note:
Combined Fleet Operations Order No. 1 issued on 5 November 1941 and titled "Preparations for War and Commencement of Hostilities" was an 89-page volume covering all phases of war preparations. In general this order stated the following:

a. The Empire is expecting war to break out with the United States, Great Britain and the Netherlands. When the decision is made to complete all operational preparations, orders will be issued establishing the approximate date (Y Day) for commencement of hostilities and announcing "First Preparations for War." When these orders are issued, the forces will act as follows:
(1) All fleets and forces, without special orders, will organize and complete battle preparations for operations in accordance with "the Allocation of Forces for First Period Operations of First Phase Operations." When directed by respective commanding officers, they will proceed at a proper time to the pre-operation rendezvous points and wait in readiness.
(2) All forces will be on strict look-out for unexpected attacks by the U.S., British, and Netherlands forces.
(3) The commanding officers of various forces may carry out such secret reconnaissance as is necessary for the operations.

APPENDIX I

Imperial Navy's Course of Action in Operations Against United States, Great Britain, and the Netherlands (Attached to Navy Directives No. 1 and No. 9)

I. Outline of Operations

Continue control over China Coast and Yangtze River.
Quickly destroy enemy fleet and air power in East Asia.
Occupy and hold strategic points in Southern Area.
Destroy enemy fleet.
Consolidate strength to hold out for a long time and destroy enemy's will to fight.

II. Combined Fleet Course of Action

(a) The First Phase of Operations

1. With the forces of the Second Fleet, Third Fleet, First Expeditionary Fleet and Eleventh Air Fleet as a nucleus destroy enemy fleets and air forces in the Philippines, British Malay, and Netherlands Indies. In cooperation with the Army, take the initiative in attacks on air forces and fleets in the Philippines and Malaya. Push forward our bases by landing advance troops. Then with main body of invasion forces occupy the Philippines and Malaya. In early stages of operations, first occupy British Borneo and then as quickly as possible occupy Dutch Borneo, Celebes and Southern Sumatra. The above to be followed by occupation of Molucca Islands and Timor. Established air bases in all of the above-mentioned places. Utilize the air bases for subjugation of Java and then occupy Java. After capture of Singapore, occupy northern Sumatra and then at an opportune time commence operations in Burma. Cut supply routes to China.
2. Forces of the Fourth Fleet.
Patrol, maintain surface communications, and defend the South Sea Islands. Capture Wake. At opportune time attack and destroy enemy advance bases in the South Pacific Area. In cooperation with Army capture Guam and then at an opportune time Bismarck Area.
3. Forces of the Fifth Fleet.
Patrol the area east of the home islands. Make preparations against surprise attacks by enemy. Make reconnaissance of Aleutians and defend Bonin Islands. Maintain surface communications. Be on guard against Soviet Russia.
4. Forces of the Sixth Fleet. (Submarines)
Make reconnaissance of American Fleet in Hawaii and West Coast areas and, by surprise attacks on shipping, destroy lines of communications.
5. Forces of First Air Fleet. (Carriers)
Hawaiian attack. Thereafter support Fourth Fleet operations and assist in capture of Southern areas.
6. Main Body of Combined Fleet.
Support operations in general. Operate according to the situation.
7. Part of Combined Fleet. (24th Commercial Destruction Unit)
Destroy enemy lines of communication in the Pacific and Indian Oceans.

(b) Second Phase of Operations.

1. Forces of Sixth Fleet. (Submarines)
Make reconnaissance and surprise attacks on main forces of enemy fleet. Destroy enemy surface communications in cooperation with a part of Combined Fleet. At opportune time make surprise attacks on enemy advanced bases.
2. Forces of First and Eleventh Air Fleets. (Carriers and Land-Based Air Forces)
Search for and attack enemy forces. Destroy enemy advanced bases.
3. Forces of Third Fleet, First Expeditionary Fleet and Other Forces as Necessary.
Defend occupied key areas in Southern area. Operate patrols, maintain surface communications, search for and destroy enemy shipping in Southern Area, attack and destroy enemy advanced bases on our perimeter.
4. Forces of Fourth Fleet.
Defend and patrol points in South Seas Islands and Bismarcks. Maintain surface communications. Search for and attack enemy shipping. Make surprise attacks and destroy enemy bases on our perimeter.
5. Forces of Fifth Fleet.
Defend Bonin Islands and patrol area to north of those islands and east of home islands. Maintain surface communications. Search for and attack enemy fleet should it appear in the area. Attack and destroy enemy bases in the Aleutians.
6. Part of Combined Fleet. (24th Commercial Destruction Unit)
Destroy enemy surface communications in Pacific and Indian Oceans.
7. Main Body of Combined Fleet.
Support all operations. Operate as required.
8. In case of attack by strong American Force.
A part of the Sixth Fleet will maintain contact with the enemy. Reduce enemy strength by air and submarine attacks. At suitable opportunity assemble major portion of Combined Fleet and destroy enemy.
9. In case of attack by strong British Force. By movement the Third Fleet, Fourth Fleet, First Expeditionary Fleet, Air Force, and Submarine Squadrons will maintain contact with enemy force and destroy it by concerted attacks. The main body of Combined Fleet, depending upon the strength, movement and location of American Fleet, will also be used in destruction of the British Fleet.
10. The important places to be defended among the points which were to be occupied were as follows: Manila*, Hong Kong, Davao, Singapore, Batavia, Surabaya* Tarakan, Balikpapan, Mendao, Makassar, Ambon, Penang, Rabaul. (Asterisk indicates advanced bases.)

III. China Area Fleet Operations

Continue operations against China. Cooperate with the Army in destruction of United States and British forces in China. Second China Fleet cooperate with Army in capture of Hong Kong and destruction of enemy forces there. Maintain surface communications along China coast. Prevent enemy from using China coast. Cooperate with Combined Fleet and Army in operations. (Escort of surface transport and defense of assembly points.)

IV. Operations of Naval District and Auxiliary Naval Station Forces

Defend assigned areas. Maintain surface communications in assigned areas. Cooperate with Combined Fleet and China Area Fleet in operations affecting assigned areas.