Mayoi Neko Overrun!

The story is about the daily life of a college freshman in the Literature Department of Tama University. He and his sister grew up on their own together after their parent's departure, but he decided to start living by himself when she got married to a man with two daughters from previous marriages. Shocked by their marriage, he attempted to distance himself from the family, leaving home before his sister gave birth to the man's third child. Approximately 3 years later he was asked by his sister to visit and babysit the girls… While he was looking after the girls, the plane which their parents were on went missing. He decided to take with him his three nieces (aged 14, 10 and 3 years old), resulting in the four of them sharing his tiny apartment.

The story revolves around Takumi Tsuzuki, a boy who lives with his older "sister" Otome, although the two have no blood ties between them. Otome manages a run-down confectionery store called Stray Cats. One day, Otome picks up a mysterious beautiful girl off the streets.

Sora-iro no Hibiki is a spin-off series of 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.