Asuka Kōzu is a female high school student with long blonde hair and blue eyes. She typically wears her school uniform or casual attire.

Her personality is cheerful, energetic, and somewhat impulsive. Asuka possesses a large appetite, frequently seen eating snacks or eagerly anticipating meals; this trait often leads to comedic situations centered on food. While generally friendly and outgoing, she startles easily and becomes flustered, particularly by unexpected events or romantic topics.

Academics are not her strength; she exhibits a lack of focus on studies and often struggles with schoolwork. Asuka enjoys leisure activities, shopping, and spending time with her close friends, Saki and Yuka. She forms one part of their core trio, her energetic nature contrasting with Saki's reserved demeanor and Yuka's studious approach.

Throughout her interactions, Asuka's traits and habits remain consistent. She reacts spontaneously to everyday events, contributes to the group's lighthearted conversations and minor conflicts, and maintains her characteristic focus on food and social activities.