Short answers, pulled from the story.
The Battle of Hong Kong began at 06:00 on the 8th of December 1941 when Japanese regiments crossed the Sham Chun River. The British surrender occurred by the afternoon of the 25th of December 1941, with isolated pockets holding out until the 27th of December.
General Christopher Maltby served as the Commander-in-Chief of the British Far East Command defending the colony. Governor Mark Young surrendered in person to General Takashi Sakai at the Peninsula Hotel on the 25th of December 1941.
Strengths included 14,564 British troops, 3,652 Local Colonial personnel, 2,428 Indian soldiers, 2,254 Auxiliary Defence Units, 2,112 Hong Kong Volunteer Defence Corps members, 1,787 Canadians, and 136 Nursing Detachment staff. A total of 96 officers, two Auxiliary Services supervisors, and 1,877 other ranks disembarked from C Force on the 16th of November.
An estimated 10,000 Hong Kong civilians were executed during the three years and eight months of Imperial Japanese administration. Japanese soldiers murdered medical personnel and wounded soldiers at Salesian Mission on the 19th of December 1941 and St. Stephen's College on the 24th of December 1941.
General Takashi Sakai led the invasion of Hong Kong and served as governor before being tried as a war criminal. He was executed by a firing squad in 1946 following the conclusion of his trial for conduct characterized by brutality and widespread war crimes.