Sora Kasugano of Yosuga no Sora

Sora Kasugano is one of Yosuga no Sora heroines. She has a twin brother and is very dependent of him. Sora couldn't care less of what others think: she would rather surf the Internet and eat instant foods, so long as Haruka is always by her side.

She is a quiet, fragile and reclusive girl, fraternal twin sister to the protagonist. Yet beneath Sora's angelic doll like appearance lies a troublesome personality that’s prone to withdrawn laziness and a rather severe lack of social graces. In episode 10, she becomes more considerate and caring towards Haruka after she decided to not trouble Haru too much and tries her best to take care of him.She seems to be very lonely when Haruka isn't with her. Also she is very jealous when she sees Haru with another girl.In the manga she tends to be more helpfull and caring towards Haruka,like cooking when he can't and she doesn't seem to spend to much time on internet.

Sora has gray eyes and silver hair. She has a perfect, doll-like appearance and is often seen as a fragile and weak girl. Whenever she goes to school (or some other places) she uses a twintail hairstyle. She usually unties her hair at home. She is 152 cm tall and is often seen carrying a rabbit doll, which she received as a present from her mother before she and Haruka left the village and which lends her a deceptively child-like character.In one picture were it's shown that she is eating with her family she is holding the spun in the right hand so we can asume she is righthanded.It's also shown that her mother was also righthanded while both her brother and father were lefthanded.

The traumatic loss of their parents, her deep bond with Haruka and a kiss she shared with him as children causes her to fantasize about him. While she shields the extent of her feelings for him in public, she experiments with herself while fantasizing about being with him. She hates Nao because of her relationship with Haruka and the fact that Nao seduced Haru when they were young. Although she hates Nao, it was implied that they were once good friends.

At the end of her route, she wins Haru's affection by confessing her love to him and making love to him as he was caring for her when she had a fever. After they get caught making love by Nao and Kozue, he attempts to break off the relationship and she attempts suicide by drowning. Haruka tries to stop her but his inability to swim only causes the both of them to sink. Sora changes her mind upon hearing him whisper "save me" and she drags Haru to shore. Afterwards, they decide to travel to a far away country, promising their friends to come back with souvenirs.