"Hetare Spiral" centers on the life of Itsuki Shindo, a high school student who struggles with self-esteem and a sense of inadequacy. Itsuki is often overshadowed by his more talented and confident peers, particularly his childhood friend and crush, Rika Aizawa, who excels in academics and sports. The narrative explores Itsuki's internal conflicts as he navigates the pressures of adolescence, societal expectations, and his desire to prove his worth.

The story begins with Itsuki joining the school's track and field team, inspired by Rika's encouragement. Despite his lack of natural athleticism, he is determined to improve and earn recognition. However, his efforts are met with setbacks, including ridicule from teammates and self-doubt. The series delves into the dynamics of the track team, highlighting the competitive yet supportive relationships among its members. Key figures include the team captain, Hiroshi Takeda, a disciplined and driven athlete who becomes a mentor to Itsuki, and Yuto Nakamura, a rival who initially dismisses Itsuki but gradually develops respect for his perseverance.

As the plot progresses, Itsuki's journey is marked by incremental growth, both physically and emotionally. He learns to confront his insecurities and embrace the value of hard work and resilience. Rika plays a pivotal role in his development, offering unwavering support while also grappling with her own challenges, including balancing her ambitions with her feelings for Itsuki. The series also touches on themes of friendship, rivalry, and the pursuit of personal goals, portraying the complexities of teenage life with a blend of humor and sincerity.

The narrative structure alternates between Itsuki's struggles on the track and his interactions with classmates, family, and mentors. Flashbacks provide insight into his past, revealing the origins of his self-doubt and the formative experiences that shape his character. The story avoids simplistic resolutions, instead emphasizing the ongoing nature of personal growth and the importance of perseverance in the face of adversity. Through Itsuki's journey, "Hetare Spiral" offers a grounded and relatable portrayal of overcoming self-doubt and striving for self-improvement.