Kurenai Mishina, one of three daughters of the late Dr. Mishina—a scientist who co-founded the secret organization MET with Dr. Kishida—inherited her father's mission after his death. She embraced the role of Musumet, utilizing a specialized helmet to harness a fallen shooting star's power and transform into Musume Red. As one of three color-coded warriors, she protects Earth from uncontrolled shooting star threats to maintain world peace. The transformation alters only her helmet, gloves, and boots, preserving whatever attire she wears during activation—school uniforms, swimwear, or casual clothing—leading to unconventional appearances in combat.

As Musume Red, the helmet grants Kurenai amplified physical strength and superhuman abilities, interfacing with her brain signals to elevate her innate capabilities to near-limitless levels. She answers urgent MET emergency calls that frequently disrupt her civilian life. Outside missions, she navigates typical adolescent experiences, attending school and pursuing romantic interests. Her personal goal of finding a partner faces complications from her Musumet duties and interactions with individuals like the affluent Saotome sisters.

Kurenai fights alongside her sisters Aoi (Musume Blue) and Midori (Musume Green) as a trio. Their endeavors balance safeguarding global stability with ordinary teenage challenges. She remains part of a collective protagonist unit centered on upholding their father's legacy.