Aaron Kwok Fu Sing in CITY UNDER SIEGE (CHUEN SING GAI BEI) during an escape was thrown into the sea to feed sharks. Earlier he breathed in poison gas that the Japanese military left during the World War II, his body mutated and absorbed a lot of sea water. He turned into a fat guy. On the way he received help from Shu Qi to get home.
Because the film involved costumes and sets that surpassed reality, the film asked William Chang Suk Ping to the art director. In addition the team also hired top Hollywood make up artists to work with the cast. This time Sing Sing's fat guy look was very difficult. For it everyday the special effect make up artist had to apply a lot of glue on his face. The entire look took four hours. Because the shoot took place in the scorching summer, Kwok Fu Sing was suffering in the cotton suit. Kwok Fu Sing said, "Everyday make up took four hours. When you wore that thick costume, you perspired immediately and were thoroughly soaked. After putting on the mask or head gear, my chin started to react and became red and swollen, even pus filled."
The most memorable for Sing Sing was the chase in the fishing village. In the film after Sing Sing came ashore he went to the fishing village. Because he was hungry and tired, he even ate salty fish. Villagers found him and chased him like a monster. Sing Sing said, "That heavy cotton suit was over 10 pounds, walking around in it took a lot of energy. I kept sweating, over one night I changed over 30 times." Shu Qi said that the Fat Guy Sing Sing look was very cute and described it as "silly". Although the shoot was very tough, Kwok Fu Sing felt it was a great experience.