This film is an adaptation of a short story of the same name, written by Kao Yi-feng. It tells the story of a green scarab beetle who has transformed into human form. As in the book, he is named "Vitamin." Vitamin surreptitiously enters people's apartments and observes and imitates human behavior. Through Vitamin's perspective as a bystander, the plot leads the audience to explore the unknown stories of various residents. However, Vitamin cannot understand the complex thoughts and desires of humans, and his short encounter with one person is fraught with doubt, conflict, and despair.

Xie Zhang-ying
as Vitamin

Huang Pei-jia
as Molly Lin

Zong-Hua Yang
as Uncle A-Shang

Hsu Hao-hsiang
as Choreographer

Jack Lee
as Chi-Wen Lee

Huang Jie-fei
as Show-Yu Chen

Hsieh Tien-ming
as Show-Yu's husband

Huang Tsai-yi
as Molly's mother

Yu-Ting Hsu
as Dancer