Miku Akiyama possesses distinctive purple eyes and pink hair, which progresses in length from neck-level during her teens to chest-length in adulthood. She is the daughter of kimono-clad flower arrangement instructor Sakura Akiyama and the sister of Asuka Akiyama. Miku's family dynamic is characterized by tension, particularly with Asuka. Miku actively pursues romantic advances toward Ryousuke, despite his engagement to Asuka. Ryousuke's lack of firm rejection leads Miku to interpret his stance as tacit approval. This situation escalates when an anonymous blackmailer confronts Miku using photographs of her interactions with Ryousuke; the scheme is later revealed to be orchestrated by Asuka, who secretly resents Miku's actions beneath a veneer of tolerance.

The family faces external threats when men invade their home seeking to humiliate Asuka. In the sequel, Miku features in a minor role alongside her sister within certain endings, though specific narrative developments are not detailed.