Spider Lilies centers on a romantic relationship between two young women, a tattoo artist and a webcam performer, and also looks at several offbeat relationships that they have with friends and relatives. A well-made movie that could have been better with a tighter plot, it often goes in unnecessary directions, and provides too little detail about its primary relationship.

Rainie Yang as the camgirl, Jade, and Isabella Leung as the tattooist, Takeko, give strong, believable performances and create likable characters, but the genesis of their romantic relationship is not adequately explored. It seems to just happen as a result of a limited childhood connection nearly ten years before, with an infatuation that could explain Jade's motivation, but does not explain why Takeko becomes obsessed with Jade, when she seems to have so little interest in almost everything else in her life. They progress from talking about tattoos and Takeko watching Jade on the internet to bed with nothing in between. Their relationships with their male admirers seem even more arbitrary and unconvincing. Takeko's relationship with her brother seems primarily designed to give her another reason to feel guilty, thereby strengthening her fixation on her past tragedies and providing a justification for her interest in Jade, since they first became acquainted in the time period in which the brother's disability began.

Spider Lilies creates two characters who its audience can care about, but then misses the opportunity to show their relationship developing, asking the audience to fill in the blanks based on abstracting their motivation from their relationships with the other characters. The result is an interesting movie that is colder than it should be, and which could have created a more believable relationship if it was less ambitious in its art and more straight forward in its telling.