How did the Japanese treated me?

At the slightest offence,punishment was swift and severe.Many anti-Japanese suspects were subjected to terrible torture or put in prison camps. The Eurasians were treated harshly because the Japanese felt they were a threat to them.They were either interned or executed.The Japanese tried to win the Indians and Malays by convincing them that Japan would free them from the British rule as they felt that they are not a threat to them.They were not spared either.Some Malays were drafted for forced labour at the 'Death Raliway' camp. The Chinese received the harshes treatment.The Japanese perceived the Chinese as a threat to their rule because they sent money to help China's resistance and they also called for a boycott of japanese goods.Some even returned to China to join in the fight against the Japanese.They were also forced to contribute 50 million dollars to Japan's war effort.

- http://historians-at-work.blogspot.sg/2007/09/how-were-people-of-singapore-treated.html

How and when did the British surrendered?

British forces in Singapore have surrendered unconditionally to the Japanese seven days after enemy troops first stormed the island, which is on the 15 February 1942

A war correspondent of the Japanese News Agency in Singapore reported that fighting ceased along the entire Malayan front at 2200 local time.

The British and Japanese commanders-in-chief, Lieutenant-General Arthur Percival and Lieutenant-General Yamashita Tomoyuki met in the Ford motor plant at the foot of Bukit Timah Hill to sign the surrender documents.

The British capitulation comes one week after Japanese forces invaded Singapore and only two weeks since their onslaught on the Malay Peninsula forced the British troops' withdrawal to the island.

- http://news.bbc.co.uk/onthisday/hi/dates/stories/february/15/newsid_3529000/3529447.stm
https://www.youtube.com/watch?v=dwvprOXGS4c

Operation Clean Up (Sook Ching Operation)

A decree was issued on Wednesday 18 February 1942: All Chinese males between the ages of 18 and 50 in Syonan-To (as Singapore was called during the Japanese Occupation) were to report to the various registration centres around the island.  The decree embodied Japanese hatred for the Chinese, cultivated through years of Sino-Japanese war since 1937.  Also, overseas Chinese had been quickly labelled anti-Japanese due to their contributions to war efforts in China.  Thus began the Sook Ching operation, or the elimination of anti-Japanese elements.

-According to the heritagetrails.sg website