Haruno Shiozaki lives with her parents in a rural mountain town, helping run their family's Niwa Café and motorcycle repair shop. She maintains a pessimistic outlook, frequently expressing a belief that significant dreams are impossible and escape from her provincial life unattainable. This contrasts sharply with her childhood self, once known for an optimistic "we won't know until we try" attitude that fueled participation in singing competitions and enthusiastic leadership of friends in activities like dirt bike riding. Experiences where her friends lacked her enthusiasm led her to dial back her ambitions to avoid inconveniencing others, fostering her current reserved and cautious demeanor.

Her daily routine involves riding her Honda Giorno moped through the countryside with motorcycle-enthusiast friends. She frequently seeks solitude at a peaceful mountainside viewpoint to reflect and drink tea, cherishing these tranquil moments. The arrival of Cynthia B. Rogers, an Australian motorcyclist working at Niwa Café, disrupts Haruno's routine and perspectives. Cynthia's free-spirited approach and global travels on her Honda CBR250R initially provoke skepticism and envy in Haruno, as Cynthia embodies the adventurous lifestyle Haruno desires but feels unattainable, forcing Haruno to confront her self-imposed limitations and internal conflicts.

A pivotal moment occurs when Cynthia takes Haruno on a spontaneous nighttime motorcycle ride to the ocean. This experience demonstrates to Haruno that relying on others' support can help overcome personal fears and expand perceived limitations, culminating in Cynthia's reassurance about the importance of accepting help. Subsequently, when friends propose forming the musical unit Poko-a-Poko ("Step by Step") to perform at the café—an idea Cynthia initially suggested—Haruno hesitates due to diminished confidence and reluctance to revisit abandoned singing ambitions. Encouragement from her friends and an encounter with Kageyama, Cynthia's motorcyclist acquaintance, leads Haruno to agree, marking a significant step in her renewed willingness to pursue incremental progress at her own pace.

Haruno commits to diligent practice with her friends for their performance, which serves as a farewell gesture for Cynthia returning to Australia. Through this process, Haruno regains some of her former optimism and makes a promise to Cynthia to eventually travel abroad for a visit. This commitment symbolizes Haruno's shift away from resignation toward actively embracing future possibilities and dreams, reflecting her ongoing journey toward self-improvement and openness to new experiences.