Miki Hoshitsuki is a first-year high school student and one of the main characters in the story. She serves as the central figure of the series, often described as the icon girl. She is a cheerful and highly energetic individual whose bright personality spreads to those around her. Her nature is kind and caring, though she can be somewhat airheaded at times. She is an innocent hard worker who always gives her best, even in difficult situations.

Her background includes being a Hoshimori, a star guardian tasked with protecting the world. She is part of the units Tiara and Princess. Her Star Dress is Phoenix, and her Star Dress Flora is Aster. In battle, she is a capable and dedicated fighter, though specific combat abilities are not detailed beyond her role as a guardian.

Her role in the story is that of a tritagonist who acts as a strong supporter for her allies, particularly Misaki, and plays a key part in saving a fallen Hoshimori and stopping the ambitions of the antagonist Iris. Her motivations are driven by a desire to feel loved and appreciated, which fuels her efforts to connect with others and protect them.

Miki’s relationships with her teammates and friends are central to her development. She grows through her bonds with others, and her cheerful demeanor often helps lift the spirits of those around her, making her a beloved and vital presence in the group. She undergoes a journey of personal growth, learning the value of teamwork and reliance on others.