Akira Endou is a violinist who initially sought to quit playing. She vowed that winning first place in a national competition would allow her to reunite with a significant romantic interest from her past. This goal remained unfulfilled when she placed second, preventing the anticipated reunion.

Her musical approach transformed after an unnamed male classmate discovered her practicing. He encouraged her to infuse genuine emotional expression into her performances, moving beyond technical proficiency. His influence became a catalyst for deeper artistic interpretation in her playing.

Her narrative arc unfolds in the episode "A Violin Sonata for a Girl" (〜少女のためのヴァイオリン・ソナタ〜). Following the departure of the inspiring classmate, she lost motivation to continue playing violin. This period of disengagement led to self-reflection, culminating in her realization about her core life priorities and the intrinsic value of her musical pursuit, separate from external validation or relationships. Her date of birth is October 31.