Otaku manga artist Nankoku Banana has given birth! While raising her first child and eldest daughter "Tantan", she eventually became pregnant with her second child. Her second daughter ``Omochi'' was born. However, there is one big problem! Her mother, Nankoku Banana, is also a "sister" and is the eldest daughter, but she has no fond memories of being a "sister". When she looks back on her childhood to adulthood, all she remembers is a verbal fight with her younger sister. The author has decided on the "Friendly Sisters Plan". It’s finally starting~♪