"Girlfriend, Girlfriend" centers around Naoya Mukai, a high school student who confesses his feelings to his childhood friend, Saki Saki, and successfully begins dating her. However, their relationship takes an unexpected turn when Nagisa Minase, another classmate, confesses her love to Naoya. Despite his commitment to Saki, Naoya is unwilling to reject Nagisa’s feelings outright. Instead, he proposes an unconventional solution: dating both Saki and Nagisa simultaneously. Saki reluctantly agrees to this arrangement, leading to a chaotic and comedic dynamic as the three navigate their unusual relationship.

The series explores the challenges and misunderstandings that arise from this polyamorous setup. Saki struggles with jealousy and insecurity, while Nagisa’s earnest and straightforward nature often complicates matters. Naoya, though well-meaning, frequently finds himself in awkward situations as he tries to balance his affections for both girls. The group’s interactions are further complicated by the arrival of Rika Hoshizaki, a childhood friend of Naoya’s who harbors her own feelings for him. Rika’s bold and assertive personality adds another layer of tension to the already precarious situation.

Throughout the series, the characters grapple with themes of love, trust, and communication. The humor stems from the absurdity of the premise and the characters’ exaggerated reactions to the increasingly convoluted scenarios. Despite the comedic tone, the story occasionally delves into more serious moments, highlighting the emotional complexities of maintaining multiple romantic relationships. The narrative maintains a lighthearted approach, focusing on the characters’ growth and their efforts to understand one another while navigating the challenges of their unconventional love triangle.