Brothers Zenta (Hayam Masao) and Sanpei (Bakuden Kozo) carelessly wile their summer away in the countryside, bullying neighbor Kintaro and fighting over who gets to deliver their father’s daily lunchbox. Sunny days come to an abrupt end when their father is accused of forging documents and put in jail. While his mother looks for work, Sanpei is sent away to stay with his father’s retired schoolmaster, but he can’t stop getting into trouble.