Kiyotaka's younger sister

Kiyotaka's younger sister is a freshman at Sanada Central High.

Appearance
Kiyotaka's younger sister is slim and of average height. She has violet eyes and dark pink hair of medium length styled in bangs. She is seen wearing the Central High uniform.

Personality
She is a shy person, barely having spoken at all in front of her brother's friends. She is also polite, and apologizes to the boys for inconveniencing them, despite it not really being her fault.

High School Boys and Old Friends
When Kiyotaka walks up to Hidenori and Yoshitake and begins talking to them, she is standing by his side silently and holding his arm. As their conversation continues, Hidenori and Yoshitake notice her glaring at them fiercely and they mistake her for Kiyotaka's girlfriend who wants to spend time alone with him.

After Kiyotaka pulls them into a nearby fast food joint, she continues glaring at them. When Kiyotaka brings up a group date he went on recently, Hidenori interrupts him for his "girlfriend's" sake, but he reveals to them that she's his younger sister who had a bad squint because she lost her contacts. At this point, she apologizes sheepishly to the boys, who've collapsed on the table.

Trivia

 * Kiyotaka and his sister are the only brother-sister pair shown in the series that attend the same school.
 * In the character popularity poll, she came in the 38th position with 158 votes.