Harue Haribara attends Oya High School alongside classmates Hotori Arashiyama and Toshiko Tatsuno, identifiable by her distinctive buck teeth, black hair, and black eyes, standing 161 cm tall. Her long-standing friendship with Hotori, Toshiko, and Futaba Kon centers on their shared participation in the school's table tennis club.

Typically quiet and unassuming in daily life, Harue transforms dramatically during table tennis matches, revealing a fiercely competitive and passionate nature. She dedicates immense effort to honing her skills, viewing the sport as fundamental to who she is. This commitment surfaces in her disapproval when Toshiko chooses shifts at the Seaside Maid Café over club practice.

Within the group, Harue often acts as a grounding counterpoint to her more eccentric friends. Her table tennis prowess occasionally influences events, like her attempt to help Futaba Kon overcome social anxiety by suggesting drumming practice would improve her ping pong footwork, demonstrating her practical, sport-focused approach to aiding peers.

Harue shares a history with Futaba Kon from middle school, where she observed Kon's isolation after an incident involving a former senpai. While initially unable to break through Kon's barriers, Harue's persistent presence as a clubmate contributed to the group's eventual unity.

Primarily functioning as part of the ensemble, Harue provides comic contrast through her sport-triggered personality shifts and her reactions to the absurd situations involving Hotori and others.