Everyone knows about the "perfect pretty girl," Kokomi Teruhashi and her famous, yet insane, older brother, Makoto Teruhashi, but nobody else knows about Kokomi's younger twin sister. Meet Mizuki Teruhashi. She's the complete opposite of her twin sister. She doesn't care that much about looks nor luxurious things like her sister. She's tough, loves rock and roll, adventurous, and isn't afraid to take risk in order to achieve for what she desires. Most of all, she would do anything to protect the ones she loves. Come meet Mizuki as she goes through the typical life of her twin sister's shadow.