Hotaru Hinase, a high school student, has always been indifferent to romantic relationships, preferring to focus on her friendships and personal interests. Her perspective begins to shift when she encounters Hananoi Saki, a classmate known for his intense and somewhat obsessive approach to love. After witnessing Hananoi’s dramatic breakup with his girlfriend, Hotaru offers him an umbrella in the rain, an act of kindness that sparks his interest in her. Hananoi, intrigued by her sincerity, confesses his feelings and asks her to date him. Though initially hesitant, Hotaru agrees to a trial relationship, curious about what love truly means.

As their relationship progresses, Hotaru navigates the complexities of romance, learning to understand her own emotions and boundaries. Hananoi, on the other hand, struggles with his overwhelming need to please and protect Hotaru, often blurring the lines between devotion and possessiveness. The series explores their evolving dynamic, highlighting the challenges of communication, trust, and emotional vulnerability. Supporting characters, such as Hotaru’s close friends and Hananoi’s family, provide additional layers to the narrative, offering insights into their personalities and backgrounds.

The story delves into themes of self-discovery, the nature of love, and the importance of mutual respect in relationships. Hotaru’s journey from emotional detachment to embracing love is central to the plot, while Hananoi’s growth involves learning to balance his intense feelings with a healthier approach to partnership. The series balances lighthearted moments with deeper emotional exploration, creating a nuanced portrayal of young love. Through its focus on character development and interpersonal dynamics, "A Condition Called Love" offers a thoughtful examination of the challenges and rewards of building a meaningful connection.