Follows the adventures of a boy who serves his military service in Unit 831 from 1969 to 1972 in preparation for a war that could erupt at anytime.

After her car breaks down on a rainy night, Miss Liang enters a nearby coffee shop called Cafe 6. The owner of the shop finds out that Miss Liang has just gotten into a fight with her boyfriend who is currently overseas, so to kill time, he shares a story of his time back in 1996. During that year, Guan Min-lu and his good friend Xiao Bo-zhi always hang out together. Min-lu is secretly in love with Li Xin-rui while Bo-zhi is attracted to Xin-rui's best friend, Cai Xin-yi. The four young teenagers share a good relationship with each other and spend their days happily every day. But as their graduation day draws near, they wonder if they can still stay committed with each other after going their separate ways.

Soon after a young police officer reports for duty, he is confronted with the unspoken rules. There are people who cannot be questioned and cases that cannot be further investigated. Although he has been sidelined, he refuses to give up the old case. However, having spent so much time and effort, will he find out the truth or some long forgotten conscience?

In 1987, as martial law ends in Taiwan, Jia-han and Birdy fall in love amid family pressure, homophobia and social stigma.