Yang Shi-Nan is a 14-year-old boy. During class one day, he finds his stomach hurting very badly. Once the class ends, he rushes to the toilet and soon notices his urine becomes bloody red.

After being diagnosed by Dr. Li Pei-Rui (48), Yang Shi-Nan has “Disorders of Sex Development,” usually known as intersex or a yin-yang human. In other words, Shi-Nan’s body contains male reproductive organs and also a female uterus, and the bloody urine is actually the menstruation.

Based on the chromosome test results, Dr. Li suggests the “sex reassignment surgery”, turning Shi-Nan into a female. He believes that Shi-Nan’s gender will eventually become synchronized biologically and psychologically. However, considering their kid is still in puberty, Shi-Nan’s parents decide to accept the surgery without telling the truth.

After the surgery, Dr. Li and the parents start giving Shi-Nan antidepressants. Under the medication influence, however, Shi-Nan’s female sex characteristics begin to grow. She gradually becomes a pretty and lovely girl. 

Her parents change her name to Yang Shi-Lan, and they move to a new city to start a new life. Shi-Lan becomes popular at new school. She has also made her first best friend, Zhang Tian-Qi (15), who helps Shi-Lan pull herself together.

However, good times don’t last forever. Shi-Lan discovers that the pills she has been taking is actually estrogen. Being both mentally and physically torn apart, she questions Dr. Li: “You say that you respect science, but have you ever respected my life? I am born to be human. I should not be treated as your medical experiment.”

The butterfly is about to break out of its chrysalis. Can Yang Shi-Lan/Yang Shi-Nan truly embrace her/his transformation?