"Cute Devil Girlfriend" centers on the life of a high school student named Haruto, whose mundane existence takes a dramatic turn when he accidentally summons a devil named Lilith. Lilith, a mischievous yet endearing demon, claims that Haruto’s summoning binds her to him as his servant. However, her true intentions remain ambiguous, as she often uses her powers to create chaotic yet comedic situations. Despite her devilish nature, Lilith gradually develops genuine feelings for Haruto, complicating their relationship.

The narrative explores the dynamic between Haruto and Lilith as they navigate the challenges of cohabitation and the clash between the human and demon worlds. Haruto, initially overwhelmed by Lilith’s antics, begins to appreciate her presence, while Lilith struggles to reconcile her demonic instincts with her growing affection for him. The story balances humor, romance, and supernatural elements, often incorporating episodic scenarios where Lilith’s powers lead to unexpected consequences.

Secondary characters include Haruto’s classmates and friends, who become entangled in the chaos caused by Lilith. Among them is Aoi, a childhood friend of Haruto who harbors unspoken feelings for him, creating a subtle love triangle. The series also introduces other supernatural beings, such as rival demons and angels, who add layers of conflict and intrigue to the plot.

Themes of trust, identity, and the nature of love are woven into the story as Haruto and Lilith confront external threats and internal dilemmas. The manga’s tone shifts between lighthearted comedy and moments of emotional depth, particularly as Lilith grapples with her dual nature and Haruto learns to accept the unpredictability of his new reality. The interplay between the human and demon worlds serves as a backdrop for character development, with the central relationship evolving amidst supernatural challenges and everyday high school life.