Hinata Kawamoto

Age: 13

Hinata is the second of the three sisters and a middle school student. She sleeps in late in the mornings until the very last minute and often makes bentos by herself. She calls Rei "Rei-chan." Like her elder sister Akari, she likes taking care of Rei. She has a strong loyalty toward her friends and family and aspires to be as mature as her sister when she gets older.

Later, she graduates from middle school, enrolls at the same high school where Rei studies, and starts dating him.
(Source: Wikipedia)