Asuna Harukaze attends Shiratama Middle School as a second-year student and actively participates in the soft tennis club. Her mornings involve assisting on the family dairy farm, including recurring comedic efforts to retrieve the escape-prone cow Hanako before school. She possesses distinctive pink hair styled with antenna-like strands, ochre eyes, stands 1.55 meters tall, and weighs 46 kilograms. Her personality exhibits extreme distractibility and a vivid imagination prone to sexual or erotic interpretations; innocent remarks often trigger explicit fantasies about teammates or rivals, sometimes providing unintended tactical advantages by unsettling opponents during matches. Despite occasional lapses in focus, she displays genuine enthusiasm for soft tennis, practicing swings with farm tools like pitchforks and prioritizing endurance through daily runs to school.

On the court, she specializes as a speed-focused player, emphasizing agility and precision over power. In doubles matches with partner Kotone Sawanatsu, she covers the backcourt to retrieve bypassed balls. However, her serves frequently strike Kotone's head accidentally, and she often trips over the court's white lines due to clumsiness. Her seasonal-themed surname "Harukaze" (spring wind) aligns with teammates' naming conventions.

She shares a friendly rivalry with Kotone and interacts with club members like the gluttonous captain Chitose Akiyama and the stoic Kurusu Fuyukawa. Former senpai Shiki Nishioka once summarized her as a "clueless pervert," reflecting the team's perception of her eccentric traits.