Haru Takigawa, the younger sister of Miu Takigawa, possesses short dark blue hair usually styled in two low pigtails and warm brown eyes. Her appearance distinctly reflects her youth as a child character.

Haru radiates a bright and cheerful personality. She visibly lights up with excitement during family moments, especially when Miu returns home. Shared family meals vividly showcase her enthusiastic demeanor. Her deep admiration for Miu's piano playing underscores the strong bond between the sisters.

Her background centers on close familial relationships. Haru lives with Miu and their mother, Sayuki Takigawa. Sayuki's collapse from overwork and subsequent hospitalization causes Haru significant emotional distress. Her profound sense of loss manifests through visible tears and expressions of missing her mother's presence, highlighting her dependence on family stability.

Haru appears during key events involving Miu's activities with the idol group 22/7. She attends Miu's first concert alongside Sayuki. Her presence is noted when technical difficulties disrupt the performance, prompting Miu to act backstage. While not directly involved in the group's activities, her attendance at such events underscores her role as part of Miu's personal motivation.

The surname "Takigawa" combines the Japanese characters for "waterfall" (Taki) and "river" (Kawa).