Mio Hagiwara begins her acting career at age 14, her passion fueled partly by a longstanding affection for her neighbor, Morimoto Teruomi. Teruomi serves as her initial motivation, making his subsequent relationship with her best friend, popular singer Aya Sawaki, particularly devastating. Amidst this heartbreak, she meets 15-year-old aspiring film director Ichiya Kumagai. Their first encounters are contentious, especially after Ichiya harshly criticizes her acting abilities, labeling her a "bad actress" due to perceived deficiencies in her line delivery, creating friction.

Despite this rocky start, Ichiya unexpectedly offers Mio comfort following her rejection by Teruomi, marking a shift in their dynamic. Mio gradually develops romantic feelings for Ichiya, even as he remains guarded and initially rejects her confession, prioritizing his directing ambitions. However, Ichiya recognizes a distinctive quality in Mio's screen presence, describing her as embodying the essence of a "handsome" woman that evokes the spirit of classic actresses. He specifically seeks her out to star in his debut film, viewing her as his ideal leading lady. This professional partnership becomes central to their evolving relationship.

Her career progresses alongside her personal development. By the conclusion of her story arc at age 17, she has navigated young love and professional growth. Additional material depicts her at age 24, still active in acting. Throughout, she demonstrates persistence in facing emotional challenges, including Ichiya's initial reluctance to reciprocate her feelings. Her experiences shape her journey from a teenager grappling with rejection into a young woman gaining assurance in both her craft and personal relationships.