Home Sweet Home (Yasuko)

Shizuka and Taro go to the same high school. A stray cat brings them together and they become friends. But when their parents remarry, they suddenly become step-brother and sister! Along with their siblings, the cool Takamasa and the strong-willed Himeko, various problems will arise. There will be love, laughter, and tears in this story set in an old house. (Source: Shogakukan, translated)