Character from Lucky Star. Due to being born the second, she's sometimes referred as a younger sister to Hiiragi Kagami, her twin sister. She is kind-hearted, but lazy and never does her homework. Tsukasa is very good at housework.
She has short purple hair usually accented with a yellow hairband tied on top, and tareme blue eyes. She also bears a resemblance to Kamigishi Akari from To Heart.
For some strange reason, leica frequently features her in fine art parodies.