Rina Koiwai 15 years old First-year high school student Childhood friend Petite and softly rounded figure, about 149 cm tall. Shoulder-length brown bob hair with a slightly springy cowlick. Her defining feature is heterochromia — her left eye is blue, her right eye is brown. Her large eyes are highly expressive. She wears a sailor-style school uniform that's a little oversized, giving her an adorably cute look. Bright and full of energy, but shy and prone to being spoiled. Innocent and brimming with curiosity. Her expressions change rapidly, from surprise to delight over the smallest things.