At 23 years old, Yuma has a dream: to become a professional manga artist. Living with profound cerebral palsy that requires her to use a wheelchair, she possesses undeniable artistic talent but is trapped in a life of suffocating dependency. Her well-meaning but overprotective mother makes every decision for her, treating her as a perpetual child rather than an adult woman. Compounding this domestic confinement is the exploitation by her childhood friend Sayaka, who passes off Yuma's artwork as her own, leaving Yuma as an invisible ghostwriter receiving neither credit nor fair compensation for her work.

Exhausted by the abuse she endures daily, Yuma makes a bold and unexpected decision. She gathers her courage and applies to draw for a magazine that publishes erotic manga. When she meets the editor-in-chief, she receives an unexpected shock: to create truly compelling works, she first needs to gain more life experience on every level. This blunt assessment sends Yuma on a quest for independence and sexual awakening, something her sheltered existence has never allowed.

Her journey leads her to venture alone into a red-light district, a world far outside her usual experience. There she meets Mai, a high-priced escort who becomes a pivotal figure in her life. Unlike her mother or Sayaka, Mai is the first person who treats Yuma as a complete, normal human being without pity or condescension. Through their friendship, Mai encourages Yuma to truly live and enjoy life, becoming her window toward freedom. Yuma also encounters Toshi, Mai's driver, who later provides her shelter when she runs away from home after her mother discovers her activities.

The narrative follows Yuma as she rebells against her mother and a society not designed for her needs. She physically struggles through inaccessible city streets, faces the constant staring of strangers, and battles the internalized belief that she does not deserve a normal life. Her quest for emancipation eventually leads her to search for the father she never knew. This search uncovers hidden family members and reveals the profound meaning behind the title 37 Seconds, a key revealed in a beautiful scene that explains how a fraction of time can change an entire existence.

Throughout her journey, Yuma moves from being a passive, shadow figure forced to remain in the background to an active agent of her own life. She rejects the prison others have constructed around her, claiming her right to love, to desire, to work under her own name, and to exist fully in the world without needing to be fixed or pitied. The manga follows her struggle not to overcome her disability according to societal standards, but to find her own path and define freedom on her own terms.