Kanade and Yukino's much younger sister.

Shizuku is a lot more level-headed than her sisters. She is deeply affected by the actions of Kanade, who she seems to care about more than Yukino. Unlike her sisters, she buries all her emotions deep down without expressing them but they later resurface in various ways, such as her cutting school. She also appears to be very passive-aggressive.

Despite Yukino's attempts to become closer to her, Shizuku clearly spurns the attention of her older sister. This is possibly due to jealousy she feels, as Kanade spends more time with Yukino, and Shizuka would prefer that Kanade pays more attention to her instead.

She seems quietly aware of the deeper relationship that her sisters may have.