Age: 16-17
Birthday: February 5
Astrological sign: Aquarius
Height: 170 cm
Hair color: silver
Eye color: light grey
Blood type: O
Known relatives: Kasugano Sora

The protagonist of the series. With a gentle appearance and slim profile, in many ways Haruka is the splitting image of his fraternal twin sister Sora. Personable and honest, he forges lasting friendships with remarkable ease. Haruka copes with the loss of his parents with a stout heart, burdened with the knowledge that the future of his delicate sister depends on him. As a result, he has a tendency to dote on his sister and worry about her constantly. He cannot swim either. The Kasugano siblings are well regarded around the village, as their grandfather was once a doctor there.