白石 ツバメ

Aoi's older sister, Shuuji's older cousin and she works at a company that makes videos for television and is also Aoi's manager. Her parents are away from home because they left to take care of the grandfather who lives in the countryside. 

After consulting with Aoi, she decided to take Shuuji in. She is often absent because of her job so she relies a lot on Aoi to take care of Shuuji and when she is at home, she mostly sleeps. She doesn't seem like a person who's taking things very seriously.

Sometimes in the evening, when Shuuji works at Comeria, she goes to see him and to eat with Aoi and spend some time with them.

She sometimes stays at parties between colleagues at the end of the day and because of her looks she receives invitations to become a model for related companies, but she herself isn't eager to do it. Also at these parties, she can hear many men models who want to "go out" (at least for one night) with Aoi.

She sincerely thinks that Aoi will take care of Shuuji and that if one day Shuuji wants to "attack" Aoi, she would very easily put him back in place (Shuuji is a healthy young man living with two pretty girls after all, so they must be wary) so in Aoi's route, she is very surprised to find that it's Aoi who "sexually" attacked Shuuji and lead their fraternal relationship to a romantic relationship. However, even if she is a little troubled by this change, she only imposes one thing on Aoi and Shuuji: use contraceptives at least until graduation./