Papa no Iukoto o Kikinasai! - Sorairo no Hibiki

Synopsis:

The eldest of the three sisters. Sora takanashi is a 2nd grader in the middle school. She is 14 years old and has a tsundere personality. She normally refers to Y?ta as "older brother (Onii-chan)". She has fairly good grades in school but is not adept at cooking. This is the spin-off story of her before the main series stated.