"Comfort women" was the Japanese imperial government's euphemism for women and girls forced into sexual slavery in Japanese military brothels from 1932 to 1945, the end of WWII. They were repeatedly raped and subjected to other forms of abuse and torture by Japanese soldiers. It is estimated that at least 400,000 women and girls were kidnapped, coerced, or duped into sexual servitude by Japanese invaders around the world. A "comfort station" typically referred to a military-run enslavement site for "comfort women" during that period.

Su points out that when the war ended, the Japanese government knew this was a shameful crime and thus systematically destroyed vast archives of evidence related to the system. The world knew very little about this part of history until a victim broke her silence in 1991. On Aug 14 that year, a 67-year-old woman from the Republic of Korea, Kim Hak-sun, courageously came forward to testify that she had been forced into sexual slavery by the Japanese military in China and later filed a lawsuit against the Japanese government.

That was also when Su first became aware of the system. His pure motivation and action came a year later when he attended an international academic conference and was asked by a Japanese scholar, "Did you know the Japanese military's first 'comfort station' was established in Shanghai?"