Mabel, Liam and Aaron have been friends since childhood. Their bonds of friendship are tested when, years later, they realize their friendship is the only reason they have made it through emotional hardships and extreme tragedies.

University student Hsu-hao longs for love. He subscribes to the “fish pond theory”, believing that he should spend time with and compare many different girls before choosing the right one. One night, Hsu-hao comes across a girl named “Koi” on a dating app and they hit it off, but the app does not match them. As he begins searching for her, a classmate recommends that he use the “Rent a Girlfriend” service. Hsu-hao ends up having a great Valentine’s Day with a girl from the service, and despite still wanting to kind Koi, he becomes inexplicably attracted to this new girl…

Shu-wei is an unpopular student who is a constant target for the school bullies, but he ends up joining forces with them when they encounter two demonic sisters who feast on human flesh in the middle of the night. The gang manage to capture one, but the other demon is angry and starts killing anyone wearing a school uniform.