Reiko Kirishima

Reiko is Ryuuki's older sister, a genius who became one of Japan's top chemists at just 24 years old. She has raised Ryuuki in place of their parents who passed away in an accident a decade ago. With her youth spent solely on studying and parenting, she knows a little of fashion or fun, giving off a somewhat vibe that doesn't attract male attention, though seems unfazed by it. She is like a mother figure to Ryuuki.