Miu is an underground idol who, along with her twin sister Yu, forms the duo known as Feathers. The pair were hired to perform at the Marukane Department Store’s Naruhata Festival, an event that brings them into the orbit of the vigilantes operating in the area. Her background as a performer in the underground idol scene places her in the entertainment side of the Naruhata district, separate from the main vigilante conflicts.

Personality-wise, Miu is described as noticeably judgmental and more openly rude than her twin sister. This trait was recognized by Makoto Tsukauchi, who labelled Miu as “the mean one” of the two. She carries herself with a sharp, critical attitude, especially in contrast to Yu’s more amiable demeanour. Her motivations as an idol are not deeply explored, but she is driven by the same pursuit of performance and recognition common to underground idols, operating without the official permissions of mainstream entertainers.

In the story, Miu appears in a supporting capacity, primarily through the Feathers’ scheduled performance at the department store event. She does not take an active role in the vigilantes’ crime-fighting activities; her significance lies in how her presence and the event itself intersect with the larger narrative. Her key relationship is with her twin sister Yu, with whom she shares a close working bond as the Feathers duo. There is no notable personal development or arc for Miu within the series; she remains a minor character defined by her role in the idol group and her contrastingly sharp personality. No specific Quirk or superhuman ability is attributed to her in the available material; her notable skill is her performance as an idol.