Papa no Iukoto wo Kikinasai! -Sora-iro no Hibiki-Echoes of Sora; Listen to me, girls. I am your father ! Sora & Miu & Hina; Papa no Iukoto o Kikinasai! - Sora-iro no Hibiki; Papa no Iukoto o Kikinasai! - Sorairo no Hibiki; Итак, девочки! Я ваш новый папа! - Песнь Соры; パパのいうことを聞きなさい! ─空色の響き─; 听爸爸的话-空色回响

Sora-iro no Hibiki is a spin-off series of Papa no iukoto wo Kikinasai! (http://mangapark.com/search?q=papa-no-iukoto-wo-kikinasai). This particular series is a prequel, starting about one year before the regular series, that tells the story of the Elder sister, Sora, and her new life as a junior high freshman.