Donten ni Warau is set during the 11th year of the Meiji era (1878). The story revolves around three brothers — Tenka, Soramaru, and Chutaro Kumou — who live in a lake side village. They are known as the "Three Kumou Brothers" of Lake Biwa.
Tenka is the oldest brother and leader of the group. He is strong-willed and determined to protect his family at all costs. Soramaru is the middle brother and has a kind heart, but can also be reckless at times. Chutaro is the youngest brother and often gets himself into trouble due to his naivety.
The Three Kumou Brothers get involved with a gang of criminals called "The Seven Spears of Shizunashi". This gang has been causing chaos in their town by committing robberies, murders, and other acts of violence. The Three Kumou Brothers must now use their wits and courage to stop The Seven Spears of Shizunashi from wreaking any more havoc on their town.
