"Scum's Wish" is a romantic drama anime that explores the complexities of unrequited love, emotional manipulation, and the darker aspects of human relationships. The story centers on Hanabi Yasuraoka and Mugi Awaya, two high school students who appear to be the perfect couple on the surface. However, their relationship is built on a fragile foundation of mutual deception. Both Hanabi and Mugi are in love with other people who do not reciprocate their feelings: Hanabi harbors feelings for her childhood friend and mentor, Narumi Kanai, while Mugi is infatuated with his piano teacher, Akane Minagawa. To cope with their loneliness and heartache, they enter into a physical relationship, using each other as substitutes for their unattainable loves.

As the story progresses, the emotional turmoil of the characters deepens. Hanabi struggles with her unresolved feelings for Narumi, who is now in a relationship with Akane, the very person Mugi desires. Akane, portrayed as manipulative and emotionally detached, uses her charm to control those around her, including Mugi and Narumi. Meanwhile, Mugi grapples with his own insecurities and the realization that his relationship with Hanabi is unsustainable. The narrative also introduces other characters, such as Sanae Ebato, a classmate who harbors a secret crush on Hanabi, and Noriko Kamomebata, a younger student who becomes entangled in the emotional web of the main characters.

The series delves into themes of jealousy, self-deception, and the pain of unfulfilled desires. It portrays the characters' struggles with their emotions and the consequences of their actions, highlighting the often messy and painful nature of human relationships. The story does not shy away from depicting the darker aspects of love, including obsession, betrayal, and the toll it takes on one's mental and emotional well-being. Through its exploration of these themes, "Scum's Wish" presents a raw and unfiltered look at the complexities of love and the lengths people go to in order to cope with their emotional wounds.