Sim Woh Kum (Chinese: 冼松锦; pinyin: Xiǎn Sōngjǐn; c. 1933 – 27 July 1973), also spelt Sim Wor Kum, was a Singaporean who was best known to be the accomplice of Mimi Wong, a bar hostess who was the first woman to be sentenced to death for murder in Singapore since its independence.

Both Sim and his wife were executed on 27 July 1973, making them the first couple to be subjected to capital punishment in Singapore since its independence in 1965.

Sim had little to no education in his childhood, and he had to help his mother Yip Kum Koi to do manual labour.

Wong, who was said to be ill-tempered since young, frequently abused her husband and used weapons on Sim whenever their arguments turned violent.

Sim, who had a mild-temper and calm personality, often silently endured these physical abuses, which at one point left a scar on his forehead.

He even ran out of the house to escape any assaults a lot of times whenever Wong picked up a knife or wooden rod.

This forced Wong having to go take up part-time jobs to support their family, including a stint at a bar as a hostess.

[4][5] In January 1970, Mimi Wong went back to her estranged husband Sim Woh Kum, then aged 37, to tell her about her plans to kill a Japanese woman.

Despite his own reservations about committing murder, Sim decided to accept the offer for he still loved Wong and he was facing huge financial troubles while alone taking care of his mother and two sons.

While she was separated from Sim, Wong met a Japanese engineer named Hiroshi Watanabe, who was a married father of three.

Upon knowing that Hiroshi was working overtime that night, Mimi Wong knew that she could take the chance to execute her plan.

After contacting Sim, Wong and her husband went together to the Jalan Sea View house where the Watanabes were spending the night.

Wong brought along a pair of gloves and a knife, while Sim took a tin half-filled with toilet-cleaning liquid, in order to pretend to be a worker coming to repair the house toilet.

He was shocked to see his three children crying over the corpse of his deceased wife, which also sparked grief to the 37-year-old mechanical engineer.

Hiroshi then asked his eldest daughter what happened, and Chieko told him that she saw Wong and a man she did not know attacking her mother.

Wong and Sim were both identified out of an identification parade by Chieko, who would become the prosecution's key witness against the couple in their trial.

[11][12] In November 1970, the trial of Mimi Wong and Sim Woh Kum began to take place.

In the aftermath of the case, both Mimi Wong and Sim Woh Kum were considered to be the first couple to be sentenced to death and executed in Singapore since its independence.

Simultaneously, Wong was also the first woman to be subjected to capital punishment in Singapore since its independence from both British colonial rule and Malaysia.

In July 2015, more than 45 years after the murder of Ayako Watanabe, Singapore's national daily newspaper The Straits Times published an e-book titled Guilty As Charged: 25 Crimes That Have Shaken Singapore Since 1965, which included the case of Mimi Wong as one of the top 25 crimes that shocked the nation since its independence in 1965.